Re: Advice about ext3, please (An experiment results)
Richard Hector wrote: On Tue, 2009-03-17 at 21:38 -0400, Stefan Monnier wrote: I was thinking to let my firewall run on a CF drive. The last one served for 10years, so ... Your firewall can probably run with near-0 writes (or even with exactly 0 writes), so your CF will easily last centuries. Especially if you can use a syslogd on another machine. Richard thanks, I should take account of that. Now it's in testing and there is nothing special I did for the filesystem. I think I should make it write as less as possible. i.e. disable swap and move stuff to memory (ram disk or so). It was helpful discussion for me. regards -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please (An experiment results)
I was thinking to let my firewall run on a CF drive. The last one served for 10years, so ... Your firewall can probably run with near-0 writes (or even with exactly 0 writes), so your CF will easily last centuries. Especially if you can use a syslogd on another machine. Or use busybox's syslogd with its circular in-memory buffer. thanks, I should take account of that. Now it's in testing and there is nothing special I did for the filesystem. I think I should make it write as less as possible. I.e. disable swap and move stuff to memory (ram disk or so). It was helpful discussion for me. I'd first check (e.g. with /proc/sys/vm/block_dump) to make sure that it's really a problem that needs solving. Stefan -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please (An experiment results)
an issue with the flash drives is their life cycle. they support about 10 writes or so in average - there was article I read recently For large enough drives, 10 writes will take several years of constant write access. So I wouldn't worry about it. Well several years is not very precise. I was thinking to let my firewall run on a CF drive. The last one served for 10years, so ... Your firewall can probably run with near-0 writes (or even with exactly 0 writes), so your CF will easily last centuries. Stefan -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please (An experiment results)
On Tue, 2009-03-17 at 21:38 -0400, Stefan Monnier wrote: I was thinking to let my firewall run on a CF drive. The last one served for 10years, so ... Your firewall can probably run with near-0 writes (or even with exactly 0 writes), so your CF will easily last centuries. Especially if you can use a syslogd on another machine. Richard -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please (An experiment results)
Stefan Monnier wrote: an issue with the flash drives is their life cycle. they support about 10 writes or so in average - there was article I read recently For large enough drives, 10 writes will take several years of constant write access. So I wouldn't worry about it. Stefan Well several years is not very precise. I was thinking to let my firewall run on a CF drive. The last one served for 10years, so ... thanks -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please (An experiment results)
an issue with the flash drives is their life cycle. they support about 10 writes or so in average - there was article I read recently For large enough drives, 10 writes will take several years of constant write access. So I wouldn't worry about it. Stefan -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please (An experiment results)
Stefan Monnier wrote: PS: typically flash memory is made up of eraseblocks that are much larger than a disk block, so depending on the way your flash key works, writing a single block (512bytes) of your disk may end up doing read the surrounding eraseblock; erase it, rewrite it with the new content of that particular block, so if the operation gets interrupted right after the erase, you may end up losing a whole bunch of nearby (but maybe unrelated) blocks. Hi, my experience with ext3 on external disk is excellent. I've been testing it last year with raid and the raid itself on usb was not very reliable, though I still have 2x200GB raided usb disks running for more than an year. But I've never had a problem with ext3 on a single usb drive an issue with the flash drives is their life cycle. they support about 10 writes or so in average - there was article I read recently regards -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
On Tue, 2009-03-10 at 12:27 +, Aneurin Price wrote: On Tue, Mar 10, 2009 at 7:18 AM, Steven Demetrius steven.demetr...@fiwwi.com wrote: On Mon, 2009-03-09 at 11:19 -0400, Stefan Monnier wrote: Does anyone here power off their computer without first shutting it down? Maybe, but after having to spend time repairing the system and/or rebuilding it or losing data they most likely don't anymore. Even if you're careful, you'll still occasionally lose power, and your machine will still occasionally crash. That's why people have developed file systems that can withstand even such situations (using journalling or a log structure). Neither ext2 nor ext3 were designed to be used in this manor. ext3 was specifically designed for these situations. Stefan This is becoming ridiculous now. You are just replying and going to extremes just because you can. Are you reading the same discussion as me? I'm here to try an help others just as I've got help in the past. Not to get into some illogical off topic discussion. I look forward to discussing other topics with you but for now this one is at end. Huh? Have completely I missed some subtext here? Or maybe parts of the thread? Stefan: The original post for this thread was a user asking whether to use ext2 or ext3 on a removable USB HD. Some people replying to the thread quoted bits and pieces of the thread and replied to those pieces. This causes confusion and leads to off topic discussions. As in this case. There are currently other posters arguing about top-posting, bottom-posting and inline-posting. With some saying they will do what they want regardless. This is nuts! The whole point to this mailing list is to help Debian users. Some of them new users. With all the off topic posts, inconsistent posting and arguments, not discussions, the mailing list seems chaotic and this does not encourage people to participate and therefore does not encourage people to use Debian. Some posters do not fully read the posting they are replying and from their posts do not give their own post much thought either. One example is saying that a good UPS costs about the same as a computer. A simple price search on the Internet will prove this wrong. This shows that the poster did not even verify the post and is just, excuse the phrase, talk out of his ass! Yes I've made mistakes, however I post corrections. I also give references so that people can go look up and read the material for themselves. Now if you think about where this thread started ( a user asking whether to use ext2 or ext3 for a removable USB HD) and where it is now what would you say. Please note that this is not a personal attack. I think I will start a few new threads and see how it goes. Maybe Staying on topic and Top vs Bottom posting. Steven. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
--- On Tue, 10/3/09, Lydgate deb...@tenebrific.ath.cx wrote: http://www.ebuyer.com/product/130477 On ebuyer it's called a Plexus V 500VA. I've read elsewhere that this is marketed under different brands/names. In the states I think it might be branded and sold by Fry's Electronics. With the risk of going even further off topic... I have one of these too, it's attached to a small via box running windows and will run for 30 minutes or so, all my other machines are on an APC. How do you find the power button on the front? Mine appears to be v' poor quality, it's fine it I don't touch it - but when I do it gets confused about turning off or switching to battery, then gets stuck in the pressed state soemtimes too. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
On Wed, Mar 11, 2009 at 6:34 AM, Steven Demetrius steven.demetr...@fiwwi.com wrote: On Tue, 2009-03-10 at 12:27 +, Aneurin Price wrote: On Tue, Mar 10, 2009 at 7:18 AM, Steven Demetrius steven.demetr...@fiwwi.com wrote: On Mon, 2009-03-09 at 11:19 -0400, Stefan Monnier wrote: Does anyone here power off their computer without first shutting it down? Maybe, but after having to spend time repairing the system and/or rebuilding it or losing data they most likely don't anymore. Even if you're careful, you'll still occasionally lose power, and your machine will still occasionally crash. That's why people have developed file systems that can withstand even such situations (using journalling or a log structure). Neither ext2 nor ext3 were designed to be used in this manor. ext3 was specifically designed for these situations. Stefan This is becoming ridiculous now. You are just replying and going to extremes just because you can. Are you reading the same discussion as me? I'm here to try an help others just as I've got help in the past. Not to get into some illogical off topic discussion. I look forward to discussing other topics with you but for now this one is at end. Huh? Have completely I missed some subtext here? Or maybe parts of the thread? Stefan: You are responding to the wrong person. The original post for this thread was a user asking whether to use ext2 or ext3 on a removable USB HD. Some people replying to the thread quoted bits and pieces of the thread and replied to those pieces. This causes confusion and leads to off topic discussions. As in this case. The only problem I've seen in this thread is you. There are currently other posters arguing about top-posting, bottom-posting and inline-posting. With some saying they will do what they want regardless. This is nuts! All with a changed subject line so it is easier to ignore. The whole point to this mailing list is to help Debian users. Some of them new users. With all the off topic posts, inconsistent posting and arguments, not discussions, the mailing list seems chaotic and this does not encourage people to participate and therefore does not encourage people to use Debian. Some posters do not fully read the posting they are replying and from their posts do not give their own post much thought either. One example is saying that a good UPS costs about the same as a computer. A simple price search on the Internet will prove this wrong. This shows that the poster did not even verify the post and is just, excuse the phrase, talk out of his ass! You know what? Fuck you. Try finding a UPS listing a load capacity of greater than 2-3 minutes for less than £200. The useful information given is that apparently they last far longer than that most of the time. In fact I spent about fifteen minutes searching for any which would be a reasonable replacement for the one we have here, which doesn't last long enough to give the machine time to shut down. Yes I've made mistakes, however I post corrections. Your contributions to this thread have ranged from useless to trolling. I also give references so that people can go look up and read the material for themselves. Now you appear to be simply lying. Now if you think about where this thread started ( a user asking whether to use ext2 or ext3 for a removable USB HD) and where it is now what would you say. Please note that this is not a personal attack. I'm unsubscribing from d-u for a few days because I've reached my monthly obnoxiousness tolerance already. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
Steven, As Aneurin has pointed out, you seem to have responded to the wrong thread, that doesn't relieve the confusion for those of us who use a list reader which threads correctly. And that is a part of what you are complaining about. I expect that you've reacted emotionally, and that is human and normal. I want to state a few more things and I will do that inline. It's going to sound patronizing but I have the grey hair to attempt that. [...] This is becoming ridiculous now. You are just replying and going to extremes just because you can. This wording is not likely to avoid an emotional reaction from the person you're trying to reply to and, thus, may be counterproductive for the discussion. It also has the potential to irritate someone if you include it in a reply to the wrong thread. I'm not even sure why this section got in your reply to Aneurin's post except you were somehow trying to answer the questions which I think were meant as rhetorical. [...] I look forward to discussing other topics with you but for now this one is at end. I hope you don't really believe that a line like that will be effective in stopping an off topic thread. Many times, these days, even a plonk won't be effective in keeping you from seeing things you don't want to see from some posters. In my opinion, it is best to ignore a lot of other posters advice, unless it is clearly incorrect, and let the OP decide what information they want from the discussion. Naturally, post to correct incorrect or dangerous advice. [...] There are currently other posters arguing about top-posting, bottom-posting and inline-posting. With some saying they will do what they want regardless. This is nuts! Nuts, perhaps. However, it happens in list after list and from time to time. Some posters come here for a social exercise and probably look on the list as some kind of slow IRC, perhaps even as a place to try and show they are smarter than others. A lot of the really knowledgeable posters who previously hung out here no longer post, I don't know if they still lurk. [..] With all the off topic posts, inconsistent posting and arguments, not discussions, the mailing list seems chaotic and this does not encourage people to participate and therefore does not encourage people to use Debian. Agreed. However, not every poster who is here to try and help others is interested in encouraging more people to use Debian. Personally, I don't care who chooses to use Debian. I will try to help those who do. Some posters do not fully read the posting they are replying and from their posts do not give their own post much thought either. I couldn't agree more. [...] I also give references so that people can go look up and read the material for themselves. [...] I think I will start a few new threads and see how it goes. Maybe Staying on topic and Top vs Bottom posting. Well, those posts are only likely to add noise to the mailing list as topics like that usually do. You state you give references when you post but it did not appear to me that you did so in the above mentioned posts. Because the topics come up so often, there would have been lots of references in the archives that you could have quoted or linked to. You didn't even mention the most basic reference, like the code of conduct on mailing lists at lists.debian.org. I think I understand your good intentions but posts like yours often act as trolls and have very little chance of changing behaviour. Submitted for your possible interest, not meant as any kind of criticism of you personally, in the hope that lurkers can learn from reading and understanding. If we can leave our egos out of discussions, the discussions benefit but it is hard for humans to do that as our emotions are affected by our daily lives, our perceptions, even our local connotations of the words used. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please (An experiment results)
The message doesn't -tell- you what to do, but what I think one should do is plug in the USB drive again and do fsck on the device. When fsck runs, in immediately reruns the journal and fixes metadata inconsistencies. Mounting the device would have done the same thing (even if mounted read-only, actually: you'd get a message along the lines of enabling read-write while replaying the journal). So running fsck is really not needed in this case. What it may not do is actually write data that was waiting in some buffer. (fsck has a option to force a full check even if the fast, incomplete check using the journal indicates that things are fixed. I did this, and fsck found no detailed errors either.) Indeed, fsck can still be useful if you want to force a full check (which mount won't do). The computer did have to be re-booted before the fsck. AFAIK this depends on many things. In my experience, the system is still perfectly usable afterwards, except that it still has some pending operations for that now-non-existent device, so you may be unable to unmount the drive and re-inserting the USB drive will usually give it some new device name (because the old one is still in use). So it has never been enough to force me to reboot, but if you do it often you will eventually need to reboot. So, yes, unplugging your USB key while it's still mounted is to be avoided, and even more so while it's being written to. Stefan -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
Stefan: The original post for this thread was a user asking whether to use ext2 or ext3 on a removable USB HD. I know. And I strongly recommend ext3 over ext2 for such a use, for the reasons explained. Feel free to disagree. But the fact is that ext3 was specifically designed to be always consistent, so that any unexpected interruption (power failure, OS crash, USB unplug, you name it) should not suffer from data loss other than the data that was being written (or to be written). Some people replying to the thread quoted bits and pieces of the thread and replied to those pieces. This causes confusion and leads to off topic discussions. As in this case. It does seem on-topic, since it goes to the core of the difference between ext2 and ext3 (reliability). There are currently other posters arguing about top-posting, bottom-posting and inline-posting. With some saying they will do what they want regardless. This is nuts! Yes, it is. AFAICT, I'm not to blame for that, I've stayed pretty focused on the topic at hand ext3 vs ext2. Stefan -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please (An experiment results)
On Wednesday 11 March 2009 17:15:44 Stefan Monnier wrote: So, yes, unplugging your USB key while it's still mounted is to be avoided, and even more so while it's being written to. The OP asked about about a USB external HDD, not a key. I have not tested the theory, but I have always understood that keys are particularly vulnerable. To physical damage if pulled out prematurely, not just damage to the filesystem. Lisi -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please (An experiment results)
Lisi Reisz wrote: I have not tested the theory, but I have always understood that keys are particularly vulnerable. To physical damage if pulled out prematurely, not just damage to the filesystem. Why so? Johannes -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please (An experiment results)
On Wednesday 11 March 2009 17:43:33 Johannes Wiedersich wrote: Lisi Reisz wrote: I have not tested the theory, but I have always understood that keys are particularly vulnerable. To physical damage if pulled out prematurely, not just damage to the filesystem. Why so? As I say, I have not tested this out myself. But I have been told it quite often. I don't know much about what is inside a USB key, and assumed that it was something to do with that. I have certainly had a USB key die when someone else yanked it out prematurely, but that could have been coincidence. Lisi -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please (An experiment results)
Lisi Reisz wrote: On Wednesday 11 March 2009 17:43:33 Johannes Wiedersich wrote: Lisi Reisz wrote: I have not tested the theory, but I have always understood that keys are particularly vulnerable. To physical damage if pulled out prematurely, not just damage to the filesystem. Why so? As I say, I have not tested this out myself. But I have been told it quite often. I don't know much about what is inside a USB key, and assumed that it was something to do with that. I have certainly had a USB key die when someone else yanked it out prematurely, but that could have been coincidence. Sorry for my misunderstanding. As you wrote about a 'theory' I thought you had some facts (although untested facts). Cheers, Johannes -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please (An experiment results)
So, yes, unplugging your USB key while it's still mounted is to be avoided, and even more so while it's being written to. The OP asked about about a USB external HDD, not a key. I have not tested the theory, but I have always understood that keys are particularly vulnerable. To physical damage if pulled out prematurely, not just damage to the filesystem. I do not know that it makes any difference, tho it's quite possible that flash keys might be more delicate, because their basic modify disk block operation may temporarily invalidate other blocks. Note that the risk is in remove while it's writing rather than remove without unmounting (tho the difference between the two is probably irrelevant to the end user). Stefan PS: typically flash memory is made up of eraseblocks that are much larger than a disk block, so depending on the way your flash key works, writing a single block (512bytes) of your disk may end up doing read the surrounding eraseblock; erase it, rewrite it with the new content of that particular block, so if the operation gets interrupted right after the erase, you may end up losing a whole bunch of nearby (but maybe unrelated) blocks. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
On Mon, 2009-03-09 at 11:19 -0400, Stefan Monnier wrote: Does anyone here power off their computer without first shutting it down? Maybe, but after having to spend time repairing the system and/or rebuilding it or losing data they most likely don't anymore. Even if you're careful, you'll still occasionally lose power, and your machine will still occasionally crash. That's why people have developed file systems that can withstand even such situations (using journalling or a log structure). Neither ext2 nor ext3 were designed to be used in this manor. ext3 was specifically designed for these situations. Stefan This is becoming ridiculous now. You are just replying and going to extremes just because you can. I'm here to try an help others just as I've got help in the past. Not to get into some illogical off topic discussion. I look forward to discussing other topics with you but for now this one is at end. Thank you Steven. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
On Mon, 2009-03-09 at 09:10 +, Nuno Magalhães wrote: On Mon, Mar 9, 2009 at 05:15, Steven Demetrius steven.demetr...@fiwwi.com wrote: Does anyone here power off their computer without first shutting it down? Maybe, but after having to spend time repairing the system and/or rebuilding it or losing data they most likely don't anymore. Power outages still occur. I was under the impression ext3 was the Good Thing™ and ext4 is the future, but with all the counter-claims i got curious. If uptime is important you'll want ext3 over ext2 (not this case i guess), if data loss is important (if?) i think the journal helps... And lately disk capacity is less and less a problem, so why not ext3? Btw, how does one know how much space is the journal using? Nuno Magalhães LU#484677 The discussion is about removable USB HD used for data backup or data transfer and whether to use ext2 or ext3 file system. Replying to and quoting only the above paragraph takes it out of contexts and changes its meaning. The solutions to power outage is to buy and install a UPS. To find out how much space is used you can look up the ext3 specification and do the calculations or format the drive with both ext2 and ext3 then note the difference in space left. Please read the entire thread for more details. Steven. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
On Tue, Mar 10, 2009 at 7:18 AM, Steven Demetrius steven.demetr...@fiwwi.com wrote: On Mon, 2009-03-09 at 11:19 -0400, Stefan Monnier wrote: Does anyone here power off their computer without first shutting it down? Maybe, but after having to spend time repairing the system and/or rebuilding it or losing data they most likely don't anymore. Even if you're careful, you'll still occasionally lose power, and your machine will still occasionally crash. That's why people have developed file systems that can withstand even such situations (using journalling or a log structure). Neither ext2 nor ext3 were designed to be used in this manor. ext3 was specifically designed for these situations. Stefan This is becoming ridiculous now. You are just replying and going to extremes just because you can. Are you reading the same discussion as me? I'm here to try an help others just as I've got help in the past. Not to get into some illogical off topic discussion. I look forward to discussing other topics with you but for now this one is at end. Huh? Have completely I missed some subtext here? Or maybe parts of the thread? -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
On Tue, Mar 10, 2009 at 6:10 AM, lists l...@fiwwi.com wrote: On Mon, 2009-03-09 at 09:10 +, Nuno Magalhães wrote: On Mon, Mar 9, 2009 at 05:15, Steven Demetrius steven.demetr...@fiwwi.com wrote: Does anyone here power off their computer without first shutting it down? Maybe, but after having to spend time repairing the system and/or rebuilding it or losing data they most likely don't anymore. Power outages still occur. I was under the impression ext3 was the Good Thing™ and ext4 is the future, but with all the counter-claims i got curious. If uptime is important you'll want ext3 over ext2 (not this case i guess), if data loss is important (if?) i think the journal helps... And lately disk capacity is less and less a problem, so why not ext3? Btw, how does one know how much space is the journal using? Nuno Magalhães LU#484677 The discussion is about removable USB HD used for data backup or data transfer and whether to use ext2 or ext3 file system. I'm surprised nobody has mentioned UDF yet. R/W support in most OSes, including recent versions of Windows. R/O support in Windows since 98 I think. It looks like a reasonable choice if the ability to be read outside of Linux is at all important. (I mention Windows specifically because it has the most limited FS support of any major OS.) Replying to and quoting only the above paragraph takes it out of contexts and changes its meaning. The solutions to power outage is to buy and install a UPS. That's not a realistic answer. A decent UPS is likely to cost as much as the computer. To find out how much space is used you can look up the ext3 specification and do the calculations or format the drive with both ext2 and ext3 then note the difference in space left. Or you could use '/sbin/debugfs -R stat 8 /dev/sda1' (substituting the correct device name for sda1 obviously), and check the size value (in bytes) on the third line. Nye -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
On Tue, Mar 10, 2009 at 12:38:25PM +, Aneurin Price wrote: That's not a realistic answer. A decent UPS is likely to cost as much as the computer. Sorry to derail the thread, but my recent experience with a UPS costing 30 GBP and which uses the megatec_usb driver for NUT suggests otherwise. It happily keeps my machine running for up to 15 minutes in a powercut and shuts it down if the battery gets too low. Works really well, has already seen action in the two months I've had it. Lydgate -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
On Tue, Mar 10, 2009 at 3:39 PM, Lydgate deb...@tenebrific.ath.cx wrote: On Tue, Mar 10, 2009 at 12:38:25PM +, Aneurin Price wrote: That's not a realistic answer. A decent UPS is likely to cost as much as the computer. Sorry to derail the thread, but my recent experience with a UPS costing 30 GBP and which uses the megatec_usb driver for NUT suggests otherwise. It happily keeps my machine running for up to 15 minutes in a powercut and shuts it down if the battery gets too low. Works really well, has already seen action in the two months I've had it. What make/model is it? All the UPSes I've looked at in that cost region claimed to have a battery life under load of more like two minutes, which isn't even certain to be long enough to shut down, depending on what you're doing with the machine. (It's fortunate that Linux systems tend to shut down fairly quickly. Windows Server 2003 seems to need *at least* 15 minutes, and shutting down is a high-load activity so battery duration is likely to be toward the lower end of the estimate.) Nye -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
On Tue, Mar 10, 2009 at 04:07:05PM +, Aneurin Price wrote: On Tue, Mar 10, 2009 at 3:39 PM, Lydgate deb...@tenebrific.ath.cx wrote: On Tue, Mar 10, 2009 at 12:38:25PM +, Aneurin Price wrote: That's not a realistic answer. A decent UPS is likely to cost as much as the computer. Sorry to derail the thread, but my recent experience with a UPS costing 30 GBP and which uses the megatec_usb driver for NUT suggests otherwise. It happily keeps my machine running for up to 15 minutes in a powercut and shuts it down if the battery gets too low. Works really well, has already seen action in the two months I've had it. What make/model is it? All the UPSes I've looked at in that cost region claimed to have a battery life under load of more like two minutes, which isn't even certain to be long enough to shut down, depending on what you're doing with the machine. (It's fortunate that Linux systems tend to shut down fairly quickly. Windows Server 2003 seems to need *at least* 15 minutes, and shutting down is a high-load activity so battery duration is likely to be toward the lower end of the estimate.) http://www.ebuyer.com/product/130477 On ebuyer it's called a Plexus V 500VA. I've read elsewhere that this is marketed under different brands/names. In the states I think it might be branded and sold by Fry's Electronics. To be fair, it is rated at 2 minutes under full load. However I only run a single HP ProLiant ML-110 G4 on it. It's Debian Lenny with just personal e-mail server and webserver. Nothing super critical but it's annoying enough when it goes down that I'd pay 33 pounds for it not to. I've measured it and this machine draws 100 VA when relatively idle, 140 VA with CPU and hard drives loaded. Lasts 15 minutes in that state. I haven't yet tested it under normal load. I mainly just want to avoid the annoyance of having it die when there's a 20 second powercut (which happens often enough in my area). The other (rare) possibility is when we completely drain our top-up electricity, and then no UPS is going to survive the cut, so in that case it just powers it down after 10 minutes or 20 minutes or however long it lasts. NUT wasn't entirely straightforward to set up as the Debian, had to manually set up 2.4.x. But it only took me an hour or so to figure out. NUT can shut down the computer (or run any other arbitrary script). Only annoyance is that the UPS beeps loudly. With NUT I set it up to send it a signal to turn off the beeps when detects battery power. The result is that it beeps once or twice then stops, which I can live with. Otherwise I couldn't be happier. For a small price, the outages have become a source of satisfaction rather than annoyance :) Lydgate -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
On Sun, Mar 08, 2009 at 11:15:43PM -0400, Stefan Monnier wrote: Journaling uses significantly more disk space and does not allow for deleted file recovery. Neither is true. I believe you're confusing log-structured file systems and journalled file systems. ext2 - for backup, removable, partitions rarely used, etc. ext2 is problematic for removable drives because if you remove the drive without cleanly unmounting it you risk losing your data. So I would recommend ext3 for such uses. Performance is rarely an issue, actually. Not unless you enable data journaling as well. And even then: not completely. The guarantee you have is that the file system will remain in a consistant state. Not that all the data will be written. -- Tzafrir Cohen | tzaf...@jabber.org | VIM is http://tzafrir.org.il || a Mutt's tzaf...@cohens.org.il || best ICQ# 16849754 || friend -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
Paul E Condon: I had pretty much decided the other way, but this, plus ... The drive is already ext3, and wikipedia article mentions problems with reverting back to ext2, which I would have to do. So, I've decided to not change, --- for now --- I didn't read the article, but ext3 is fully backwards-compatible with ext2. Just mount the (previously cleanly unmounted) filesystem as ext2 and it works. J. -- I throw away plastics and think about the discoveries of future archeologists. [Agree] [Disagree] http://www.slowlydownward.com/NODATA/data_enter2.html signature.asc Description: Digital signature
Re: Advice about ext3, please
On Sun, Mar 08, 2009 at 21:31:15 -0600, Paul E Condon (pecon...@mesanetworks.net) wrote: On 2009-03-08_23:15:43, Stefan Monnier wrote: Journaling uses significantly more disk space and does not allow for deleted file recovery. Neither is true. I believe you're confusing log-structured file systems and journalled file systems. ext2 - for backup, removable, partitions rarely used, etc. ext2 is problematic for removable drives because if you remove the drive without cleanly unmounting it you risk losing your data. So I would recommend ext3 for such uses. Performance is rarely an issue, actually. Stefan That is a pretty persuasive argument. I can see the plug being pulled by accident fairly often in the long run. ;-) I had pretty much decided the other way, but this, plus ... The drive is already ext3, and wikipedia article mentions problems with reverting back to ext2, which I would have to do. So, I've decided to not change, --- for now --- One good reason for using ext2 is to help reduce the number of disk writes - which if your USB drive is a flash memory device rather than a traditional hard disk might be considered important. Otherwise, it probably makes sense to do as you have decided and stick with ext3. -- Bob Cox. Stoke Gifford, near Bristol, UK. Please reply to the list only. Do NOT send copies directly to me. Debian on the NSLU2: http://bobcox.com/slug/ -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
On Mon, Mar 9, 2009 at 05:15, Steven Demetrius steven.demetr...@fiwwi.com wrote: Does anyone here power off their computer without first shutting it down? Maybe, but after having to spend time repairing the system and/or rebuilding it or losing data they most likely don't anymore. Power outages still occur. I was under the impression ext3 was the Good Thing™ and ext4 is the future, but with all the counter-claims i got curious. If uptime is important you'll want ext3 over ext2 (not this case i guess), if data loss is important (if?) i think the journal helps... And lately disk capacity is less and less a problem, so why not ext3? Btw, how does one know how much space is the journal using? Nuno Magalhães LU#484677 -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
On Sun, 08 Mar 2009 21:31:15 -0600, Paul E Condon wrote: That is a pretty persuasive argument. I can see the plug being pulled by accident fairly often in the long run. ;-) Suggest you mount that drive with the sync option. Might make it a little less likely that you'll pull the plug while the data is being written. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
ext2 is problematic for removable drives because if you remove the drive without cleanly unmounting it you risk losing your data. So I would recommend ext3 for such uses. Performance is rarely an issue, actually. I use ext3 for my external USB drive. Does this mean that I can remove it without cleanly unmounting it and not need to worry, or do you merely mean that I'd be less likely to lose data than if I'd use ext2? Unmounting is always necessary if you want to make sure that your changes are written to the disk, unless your filesystem doesn't do any caching at all (don't know of any that does that, though there used to be something called supermount to do that). But with ext3, if you remove the drive without unmounting it, you should expect to still have all your previous data: some of the recent changes may be missing, but that's it. With ext2 OTOH you may lose any part of your disk's content, even files you haven't touched in a long while. In practice fsck does a good job of recovering from such damage on ext2 (fsck is usually not needed at all for ext3). Stefan -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
Does anyone here power off their computer without first shutting it down? Maybe, but after having to spend time repairing the system and/or rebuilding it or losing data they most likely don't anymore. Even if you're careful, you'll still occasionally lose power, and your machine will still occasionally crash. That's why people have developed file systems that can withstand even such situations (using journalling or a log structure). Neither ext2 nor ext3 were designed to be used in this manor. ext3 was specifically designed for these situations. Stefan -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please (An experiment results)
On 2009-03-09_11:19:38, Stefan Monnier wrote: Does anyone here power off their computer without first shutting it down? Maybe, but after having to spend time repairing the system and/or rebuilding it or losing data they most likely don't anymore. Even if you're careful, you'll still occasionally lose power, and your machine will still occasionally crash. That's why people have developed file systems that can withstand even such situations (using journalling or a log structure). Neither ext2 nor ext3 were designed to be used in this manor. ext3 was specifically designed for these situations. I did an experiment. I was worried particularly about an accidental unplugging of USB before umount. What happens when you pull the plug is that the kernel issues an alert on all functioning consoles and terminal emulators to the effect journaling has failed. It is hard, very hard to be unaware that you, the operator, have made a mistake. The message doesn't -tell- you what to do, but what I think one should do is plug in the USB drive again and do fsck on the device. When fsck runs, in immediately reruns the journal and fixes metadata inconsistencies. What it may not do is actually write data that was waiting in some buffer. (fsck has a option to force a full check even if the fast, incomplete check using the journal indicates that things are fixed. I did this, and fsck found no detailed errors either.) In an archiving application, which is what I am interested in, the data is a stable record that has been prepared for archiving, so rerunning the archiving software fixes any incomplete writes. With less robust file systems, the file system can become corrupted to the point that it must be reformatted. That would be really not good. The computer did have to be re-booted before the fsck. the kernel behaved as it a journal error was equivalent to a kerneloops. So pulling the plug accidentally is a fairly big deal in a situation where 100% up-time is required, But, again there are ways to design around this, like having the USB drive connected to a computer that is dedicated to archiving, and is expected to go down from time to time due to operator error. I haven't looked into power failure during archiving, but I reason that this is not a problem -for- -archiving-. The record that has been prepared for archive is not being modified when the power fails, so there is little chance that it will be damaged. The file system on the USB maybe damaged, but, with the journal, can be fixed before it is remounted to resume the archiving process. So I conclude ext3 is good for archiving. -- Paul E Condon pecon...@mesanetworks.net -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
On 2009-03-08_12:58:14, Steven Demetrius wrote: Paul E Condon wrote: I'd like some confirmation, or refutation, of some reasoning: I have a USB external hard drive. It came with vfat fs, but I want to write an ext2/3 fs on it. All my internal HD are ext3, but should this one be ext3, also? Doesn't ext3 essentially write everything twice, first to the journal, and then to the actual target location? This is OK with an internal bus interface from the CPU to the HD, but USB is not so fast. So I think I should not use ext3 for this HD. Is this correct? TIA Basically ext3 is ext2 with Journaling. Journaling basically safe-guards against power failure and system crashes. It is well suited for system partitions and partitions that are being used most of the time your computer is on. Journaling uses significantly more disk space and does not allow for deleted file recovery. IT uses more resources that ext2. Journaling does not write everything twice. It keeps track of the file system which makes recovery fast and more reliable than file systems without Journaling. I recommend the following: ext3 - for system partitions and data partitions which are in use most of the time (/, /home, /var, etc. if they are separate partitions or drives). ext2 - for backup, removable, partitions rarely used, etc. If your USB external is for backup or file transfers then I recommend using the ext2 file system on it. Logic being that if your USB external data gets corrupted then you still have a copy of the data on another partition. FYI: Some people confuse backup with archiving. They will make copies of their data and store it away until they have data problems with the system. This is archiving. Backup is a never ending routine whether done once a week or one a month and also include regular data integrity checks of the backups. I turned 76 last Dec. I've followed digital electronic computing since I was in high school in late '40s. That was way back when digital computers would seldom run for more than a few hours or a day without crashing. Back then, people regularly ran what they called 'check points'. These were records of the current state of the unfinished computation in a format that was suitable for restarting the computer after the offending vacuum tube was found and replaced. Often, the last check point record was unreadable, whatever the recording medium, and they had to find the last *good* check point. Then, they would 'back up' to that last good check point and resume the calculation from that poing. Over time, the jargon has changed. The word backup now means what was once called 'writing a check point'. Back then, I think there was little idea of archiving as it is thought of today, namely a permanent historical record. Check points were written onto flaky (literally) magnetic tape, or punched paper tape. Any idea of permanence of such records seemed rediculous. I show my age by calling my nightly backups check points. They are written on a separate HD on a separate computer. Now, I am working on a system for archiving my check points onto an external HD. Your comments are helpful reinforcement of my inclinations, but see Sven's earlier comment. The current default for mount of ext3fs seems not to be so costly as you or I have supposed. There is a very costly option, but it is not the default. Thanks. -- Paul E Condon pecon...@mesanetworks.net -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
On 2009-03-08_13:41:53, Lists wrote: Steven Demetrius wrote: Paul E Condon wrote: I'd like some confirmation, or refutation, of some reasoning: I have a USB external hard drive. It came with vfat fs, but I want to write an ext2/3 fs on it. All my internal HD are ext3, but should this one be ext3, also? Doesn't ext3 essentially write everything twice, first to the journal, and then to the actual target location? This is OK with an internal bus interface from the CPU to the HD, but USB is not so fast. So I think I should not use ext3 for this HD. Is this correct? TIA Basically ext3 is ext2 with Journaling. Journaling basically safe-guards against power failure and system crashes. It is well suited for system partitions and partitions that are being used most of the time your computer is on. Journaling uses significantly more disk space and does not allow for deleted file recovery. IT uses more resources that ext2. Journaling does not write everything twice. It keeps track of the file system which makes recovery fast and more reliable than file systems without Journaling. I recommend the following: ext3 - for system partitions and data partitions which are in use most of the time (/, /home, /var, etc. if they are separate partitions or drives). ext2 - for backup, removable, partitions rarely used, etc. If your USB external is for backup or file transfers then I recommend using the ext2 file system on it. Logic being that if your USB external data gets corrupted then you still have a copy of the data on another partition. FYI: Some people confuse backup with archiving. They will make copies of their data and store it away until they have data problems with the system. This is archiving. Backup is a never ending routine whether done once a week or one a month and also include regular data integrity checks of the backups. Correction: Journaling file system does write data twice. ttp://en.wikipedia.org/wiki/Ext3 This is an interesting reference. I think I am convinced that journaling in Linux is -not- a finished story. Thanks for pointing it out. -- Paul E Condon pecon...@mesanetworks.net -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
Paul E Condon wrote: On 2009-03-08_12:58:14, Steven Demetrius wrote: Paul E Condon wrote: I'd like some confirmation, or refutation, of some reasoning: I have a USB external hard drive. It came with vfat fs, but I want to write an ext2/3 fs on it. All my internal HD are ext3, but should this one be ext3, also? Doesn't ext3 essentially write everything twice, first to the journal, and then to the actual target location? This is OK with an internal bus interface from the CPU to the HD, but USB is not so fast. So I think I should not use ext3 for this HD. Is this correct? TIA Basically ext3 is ext2 with Journaling. Journaling basically safe-guards against power failure and system crashes. It is well suited for system partitions and partitions that are being used most of the time your computer is on. Journaling uses significantly more disk space and does not allow for deleted file recovery. IT uses more resources that ext2. Journaling does not write everything twice. It keeps track of the file system which makes recovery fast and more reliable than file systems without Journaling. I recommend the following: ext3 - for system partitions and data partitions which are in use most of the time (/, /home, /var, etc. if they are separate partitions or drives). ext2 - for backup, removable, partitions rarely used, etc. If your USB external is for backup or file transfers then I recommend using the ext2 file system on it. Logic being that if your USB external data gets corrupted then you still have a copy of the data on another partition. FYI: Some people confuse backup with archiving. They will make copies of their data and store it away until they have data problems with the system. This is archiving. Backup is a never ending routine whether done once a week or one a month and also include regular data integrity checks of the backups. I turned 76 last Dec. I've followed digital electronic computing since I was in high school in late '40s. That was way back when digital computers would seldom run for more than a few hours or a day without crashing. Back then, people regularly ran what they called 'check points'. These were records of the current state of the unfinished computation in a format that was suitable for restarting the computer after the offending vacuum tube was found and replaced. Often, the last check point record was unreadable, whatever the recording medium, and they had to find the last *good* check point. Then, they would 'back up' to that last good check point and resume the calculation from that poing. Over time, the jargon has changed. The word backup now means what was once called 'writing a check point'. Back then, I think there was little idea of archiving as it is thought of today, namely a permanent historical record. Check points were written onto flaky (literally) magnetic tape, or punched paper tape. Any idea of permanence of such records seemed rediculous. I show my age by calling my nightly backups check points. They are written on a separate HD on a separate computer. Now, I am working on a system for archiving my check points onto an external HD. Your comments are helpful reinforcement of my inclinations, but see Sven's earlier comment. The current default for mount of ext3fs seems not to be so costly as you or I have supposed. There is a very costly option, but it is not the default. Thanks. Paul congratulations on your 76th and thank you for the history lessen. It very interesting and most times funny how computer jargon evolves. Thank you for your positive comments. I've looked at Sven's earlier comments. If there is a concern with compatibility with older systems then ext2 would be the way to go. If the default mount option is to not enable write to journal then that does reduce amount of resources used. However, journaling still requires more disk space for file system management which in a data backup or data transfer HD would be better used for data storage. Here I'm talking about the journaling database used to track changes on the file system to be used for recovery. I don't see any advantage in using ext3 over ext2 for data backup or data transfer. I do see some disadvantages. However in the grand scheme of things these disadvantages maybe negligible. The main issue here is the amount of disk space used for maintaining the file system which affects the amount of space available for data storage. An Internet search would be a good way to get detailed comparison on advantages and disadvantages of ext2 and ext3. Thanks you. Steven -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
Paul E Condon wrote: On 2009-03-08_13:41:53, Lists wrote: Steven Demetrius wrote: Paul E Condon wrote: I'd like some confirmation, or refutation, of some reasoning: I have a USB external hard drive. It came with vfat fs, but I want to write an ext2/3 fs on it. All my internal HD are ext3, but should this one be ext3, also? Doesn't ext3 essentially write everything twice, first to the journal, and then to the actual target location? This is OK with an internal bus interface from the CPU to the HD, but USB is not so fast. So I think I should not use ext3 for this HD. Is this correct? TIA Basically ext3 is ext2 with Journaling. Journaling basically safe-guards against power failure and system crashes. It is well suited for system partitions and partitions that are being used most of the time your computer is on. Journaling uses significantly more disk space and does not allow for deleted file recovery. IT uses more resources that ext2. Journaling does not write everything twice. It keeps track of the file system which makes recovery fast and more reliable than file systems without Journaling. I recommend the following: ext3 - for system partitions and data partitions which are in use most of the time (/, /home, /var, etc. if they are separate partitions or drives). ext2 - for backup, removable, partitions rarely used, etc. If your USB external is for backup or file transfers then I recommend using the ext2 file system on it. Logic being that if your USB external data gets corrupted then you still have a copy of the data on another partition. FYI: Some people confuse backup with archiving. They will make copies of their data and store it away until they have data problems with the system. This is archiving. Backup is a never ending routine whether done once a week or one a month and also include regular data integrity checks of the backups. Correction: Journaling file system does write data twice. ttp://en.wikipedia.org/wiki/Ext3 This is an interesting reference. I think I am convinced that journaling in Linux is -not- a finished story. Thanks for pointing it out. Paul: Did you take a look at the ext4 file system? Looking very interesting. Especially deframentation. Thank you Steven. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
On 2009-03-09_09:20:06, Steven Demetrius wrote: Paul E Condon wrote: On 2009-03-08_13:41:53, Lists wrote: Steven Demetrius wrote: Paul E Condon wrote: I'd like some confirmation, or refutation, of some reasoning: I have a USB external hard drive. It came with vfat fs, but I want to write an ext2/3 fs on it. All my internal HD are ext3, but should this one be ext3, also? Doesn't ext3 essentially write everything twice, first to the journal, and then to the actual target location? This is OK with an internal bus interface from the CPU to the HD, but USB is not so fast. So I think I should not use ext3 for this HD. Is this correct? TIA Basically ext3 is ext2 with Journaling. Journaling basically safe-guards against power failure and system crashes. It is well suited for system partitions and partitions that are being used most of the time your computer is on. Journaling uses significantly more disk space and does not allow for deleted file recovery. IT uses more resources that ext2. Journaling does not write everything twice. It keeps track of the file system which makes recovery fast and more reliable than file systems without Journaling. I recommend the following: ext3 - for system partitions and data partitions which are in use most of the time (/, /home, /var, etc. if they are separate partitions or drives). ext2 - for backup, removable, partitions rarely used, etc. If your USB external is for backup or file transfers then I recommend using the ext2 file system on it. Logic being that if your USB external data gets corrupted then you still have a copy of the data on another partition. FYI: Some people confuse backup with archiving. They will make copies of their data and store it away until they have data problems with the system. This is archiving. Backup is a never ending routine whether done once a week or one a month and also include regular data integrity checks of the backups. Correction: Journaling file system does write data twice. ttp://en.wikipedia.org/wiki/Ext3 This is an interesting reference. I think I am convinced that journaling in Linux is -not- a finished story. Thanks for pointing it out. Paul: Did you take a look at the ext4 file system? Looking very interesting. Especially deframentation. I read the description in wikipedia. We will all be doing ext4 in near future, I think. But for now, my project is making an archive of my check points. For this application I think ext2 provides a tiny decrease in overhead, for an infinitessimal increase in unreliability. For this app., there is always the option of a total re-run of any single job. Other issues like USB 2.0 vs USB 1.1 loom -much- larger. -- Paul E Condon pecon...@mesanetworks.net -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
Journaling uses significantly more disk space and does not allow for deleted file recovery. Neither is true. I believe you're confusing log-structured file systems and journalled file systems. ext2 - for backup, removable, partitions rarely used, etc. ext2 is problematic for removable drives because if you remove the drive without cleanly unmounting it you risk losing your data. So I would recommend ext3 for such uses. Performance is rarely an issue, actually. Stefan -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
On Sun, 08 Mar 2009 23:15:43 -0400 Stefan Monnier monn...@iro.umontreal.ca wrote: ... ext2 is problematic for removable drives because if you remove the drive without cleanly unmounting it you risk losing your data. So I would recommend ext3 for such uses. Performance is rarely an issue, actually. I use ext3 for my external USB drive. Does this mean that I can remove it without cleanly unmounting it and not need to worry, or do you merely mean that I'd be less likely to lose data than if I'd use ext2? Celejar -- mailmin.sourceforge.net - remote access via secure (OpenPGP) email ssuds.sourceforge.net - A Simple Sudoku Solver and Generator -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
On 2009-03-08_23:15:43, Stefan Monnier wrote: Journaling uses significantly more disk space and does not allow for deleted file recovery. Neither is true. I believe you're confusing log-structured file systems and journalled file systems. ext2 - for backup, removable, partitions rarely used, etc. ext2 is problematic for removable drives because if you remove the drive without cleanly unmounting it you risk losing your data. So I would recommend ext3 for such uses. Performance is rarely an issue, actually. Stefan That is a pretty persuasive argument. I can see the plug being pulled by accident fairly often in the long run. ;-) I had pretty much decided the other way, but this, plus ... The drive is already ext3, and wikipedia article mentions problems with reverting back to ext2, which I would have to do. So, I've decided to not change, --- for now --- Thanks. -- Paul E Condon pecon...@mesanetworks.net -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
On 2009-03-08_23:25:53, Celejar wrote: On Sun, 08 Mar 2009 23:15:43 -0400 Stefan Monnier monn...@iro.umontreal.ca wrote: ... ext2 is problematic for removable drives because if you remove the drive without cleanly unmounting it you risk losing your data. So I would recommend ext3 for such uses. Performance is rarely an issue, actually. I use ext3 for my external USB drive. Does this mean that I can remove it without cleanly unmounting it and not need to worry, or do you merely mean that I'd be less likely to lose data than if I'd use ext2? Celejar I think it is not quite so robust as that. From reading wikipedia, I think fsck can clean up the mess, faster and more reliably if journal is available. I think. I'm not sure. But surely your better off with journaling than without when you accidentally pull the plug too soon. And one thing I know for sure about me. I make mistakes. -- Paul E Condon pecon...@mesanetworks.net -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
Paul E Condon wrote: On 2009-03-09_09:20:06, Steven Demetrius wrote: Paul E Condon wrote: On 2009-03-08_13:41:53, Lists wrote: Steven Demetrius wrote: Paul E Condon wrote: I'd like some confirmation, or refutation, of some reasoning: I have a USB external hard drive. It came with vfat fs, but I want to write an ext2/3 fs on it. All my internal HD are ext3, but should this one be ext3, also? Doesn't ext3 essentially write everything twice, first to the journal, and then to the actual target location? This is OK with an internal bus interface from the CPU to the HD, but USB is not so fast. So I think I should not use ext3 for this HD. Is this correct? TIA Basically ext3 is ext2 with Journaling. Journaling basically safe-guards against power failure and system crashes. It is well suited for system partitions and partitions that are being used most of the time your computer is on. Journaling uses significantly more disk space and does not allow for deleted file recovery. IT uses more resources that ext2. Journaling does not write everything twice. It keeps track of the file system which makes recovery fast and more reliable than file systems without Journaling. I recommend the following: ext3 - for system partitions and data partitions which are in use most of the time (/, /home, /var, etc. if they are separate partitions or drives). ext2 - for backup, removable, partitions rarely used, etc. If your USB external is for backup or file transfers then I recommend using the ext2 file system on it. Logic being that if your USB external data gets corrupted then you still have a copy of the data on another partition. FYI: Some people confuse backup with archiving. They will make copies of their data and store it away until they have data problems with the system. This is archiving. Backup is a never ending routine whether done once a week or one a month and also include regular data integrity checks of the backups. Correction: Journaling file system does write data twice. ttp://en.wikipedia.org/wiki/Ext3 This is an interesting reference. I think I am convinced that journaling in Linux is -not- a finished story. Thanks for pointing it out. Paul: Did you take a look at the ext4 file system? Looking very interesting. Especially deframentation. I read the description in wikipedia. We will all be doing ext4 in near future, I think. But for now, my project is making an archive of my check points. For this application I think ext2 provides a tiny decrease in overhead, for an infinitessimal increase in unreliability. For this app., there is always the option of a total re-run of any single job. Other issues like USB 2.0 vs USB 1.1 loom -much- larger. Sorry I didn't mean that ext4 should be used for removable drives or backup. Just bringing attention to it and that it includes deframentation capabilities. Looks like we are starting a new thread here. Steven. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
Paul E Condon wrote: On 2009-03-08_23:25:53, Celejar wrote: On Sun, 08 Mar 2009 23:15:43 -0400 Stefan Monnier monn...@iro.umontreal.ca wrote: ... ext2 is problematic for removable drives because if you remove the drive without cleanly unmounting it you risk losing your data. So I would recommend ext3 for such uses. Performance is rarely an issue, actually. I use ext3 for my external USB drive. Does this mean that I can remove it without cleanly unmounting it and not need to worry, or do you merely mean that I'd be less likely to lose data than if I'd use ext2? Celejar I think it is not quite so robust as that. From reading wikipedia, I think fsck can clean up the mess, faster and more reliably if journal is available. I think. I'm not sure. But surely your better off with journaling than without when you accidentally pull the plug too soon. And one thing I know for sure about me. I make mistakes. Does anyone here power off their computer without first shutting it down? Maybe, but after having to spend time repairing the system and/or rebuilding it or losing data they most likely don't anymore. Lose one's data a few times after removing the drive without unmounting it will change one's behavior to checking before unplugging. Neither ext2 nor ext3 were designed to be used in this manor. Even with it superior recovery system ext3 can still suffer from total data loss if used in this manor. Steven -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Advice about ext3, please
I'd like some confirmation, or refutation, of some reasoning: I have a USB external hard drive. It came with vfat fs, but I want to write an ext2/3 fs on it. All my internal HD are ext3, but should this one be ext3, also? Doesn't ext3 essentially write everything twice, first to the journal, and then to the actual target location? This is OK with an internal bus interface from the CPU to the HD, but USB is not so fast. So I think I should not use ext3 for this HD. Is this correct? TIA -- Paul E Condon pecon...@mesanetworks.net -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
On 2009-03-07 21:30 +0100, Paul E Condon wrote: I'd like some confirmation, or refutation, of some reasoning: I have a USB external hard drive. It came with vfat fs, but I want to write an ext2/3 fs on it. All my internal HD are ext3, but should this one be ext3, also? That would be okay, unless you need to access it from systems that cannot read ext3. Doesn't ext3 essentially write everything twice, first to the journal, and then to the actual target location? No, unless you use the mount option data=journal. See the Mount options for ext3 section in mount(8). This is OK with an internal bus interface from the CPU to the HD, but USB is not so fast. So I think I should not use ext3 for this HD. Is this correct? AFAIK there are no special disadvantages in using ext3 for external hard disks. Sven -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
Paul E Condon wrote: I'd like some confirmation, or refutation, of some reasoning: I have a USB external hard drive. It came with vfat fs, but I want to write an ext2/3 fs on it. All my internal HD are ext3, but should this one be ext3, also? Doesn't ext3 essentially write everything twice, first to the journal, and then to the actual target location? This is OK with an internal bus interface from the CPU to the HD, but USB is not so fast. So I think I should not use ext3 for this HD. Is this correct? TIA Basically ext3 is ext2 with Journaling. Journaling basically safe-guards against power failure and system crashes. It is well suited for system partitions and partitions that are being used most of the time your computer is on. Journaling uses significantly more disk space and does not allow for deleted file recovery. IT uses more resources that ext2. Journaling does not write everything twice. It keeps track of the file system which makes recovery fast and more reliable than file systems without Journaling. I recommend the following: ext3 - for system partitions and data partitions which are in use most of the time (/, /home, /var, etc. if they are separate partitions or drives). ext2 - for backup, removable, partitions rarely used, etc. If your USB external is for backup or file transfers then I recommend using the ext2 file system on it. Logic being that if your USB external data gets corrupted then you still have a copy of the data on another partition. FYI: Some people confuse backup with archiving. They will make copies of their data and store it away until they have data problems with the system. This is archiving. Backup is a never ending routine whether done once a week or one a month and also include regular data integrity checks of the backups. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
Re: Advice about ext3, please
Steven Demetrius wrote: Paul E Condon wrote: I'd like some confirmation, or refutation, of some reasoning: I have a USB external hard drive. It came with vfat fs, but I want to write an ext2/3 fs on it. All my internal HD are ext3, but should this one be ext3, also? Doesn't ext3 essentially write everything twice, first to the journal, and then to the actual target location? This is OK with an internal bus interface from the CPU to the HD, but USB is not so fast. So I think I should not use ext3 for this HD. Is this correct? TIA Basically ext3 is ext2 with Journaling. Journaling basically safe-guards against power failure and system crashes. It is well suited for system partitions and partitions that are being used most of the time your computer is on. Journaling uses significantly more disk space and does not allow for deleted file recovery. IT uses more resources that ext2. Journaling does not write everything twice. It keeps track of the file system which makes recovery fast and more reliable than file systems without Journaling. I recommend the following: ext3 - for system partitions and data partitions which are in use most of the time (/, /home, /var, etc. if they are separate partitions or drives). ext2 - for backup, removable, partitions rarely used, etc. If your USB external is for backup or file transfers then I recommend using the ext2 file system on it. Logic being that if your USB external data gets corrupted then you still have a copy of the data on another partition. FYI: Some people confuse backup with archiving. They will make copies of their data and store it away until they have data problems with the system. This is archiving. Backup is a never ending routine whether done once a week or one a month and also include regular data integrity checks of the backups. Correction: Journaling file system does write data twice. ttp://en.wikipedia.org/wiki/Ext3 -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of unsubscribe. Trouble? Contact listmas...@lists.debian.org
