Re: RAMdisk, not for boot, how?
On Fri, Mar 28, 2008 at 01:21:55PM +1100, Rod Whitworth wrote: On Fri, 28 Mar 2008 02:51:33 +0100, chefren wrote: On 3/28/08 1:20 AM, Rod Whitworth wrote: The CF wearout meme needs to die. Specs, it's all about specs, it seems a fact to me that standard CF cards, as used in camera's, often without any technical specification other than size, cannot be written as often as ordinary harddisks. [snip brand examples] I have lost cout of failed HDDs around here and never lost a byte on CF. There are nearly as many CFs here as HDDs now and if you have a look at new laptops you'll see more and more SSHD and hybrids every time a new model comes out. Practically speaking if you buy a decent brand of CF or spend the extra on an industrial model you can expect years of service out of it. I'm sure that Bamboo Charlie makes cheapies in CF as well as mobos and other junk, don't buy from him I have my old IBM ValuePoint 486 that has a bios that really only likes drives under 512 MB. It has worked with one 8 GB drive, but not another seemingly identical WD 8 GB drive, yet alone a new-off-the-shelf 80 GB PATA drive. The IBM bios has no adjustability (as does the Award bios), but instead just displays the size of the hard drive found. If it displays a size, it will boot from it, if not, it declares a hardware error and won't boot from anything. I wonder if a 512 MB CF card in a PATA-CF adapter would be a solution in this case. The box would likely do remote-logging anyway. Does a CF card in a PATA-CF adapter look just like a HD, bootable and all, to old BIOS? Doug.
Re: RAMdisk, not for boot, how?
On 2008-03-29, Douglas A. Tutty [EMAIL PROTECTED] wrote: I have my old IBM ValuePoint 486 that has a bios that really only likes drives under 512 MB. It has worked with one 8 GB drive, but not another seemingly identical WD 8 GB drive, yet alone a new-off-the-shelf 80 GB PATA drive. The IBM bios has no adjustability (as does the Award bios), but instead just displays the size of the hard drive found. If it displays a size, it will boot from it, if not, it declares a hardware error and won't boot from anything. I wonder if a 512 MB CF card in a PATA-CF adapter would be a solution in this case. The box would likely do remote-logging anyway. Does a CF card in a PATA-CF adapter look just like a HD, bootable and all, to old BIOS? Yes, totally. I think this has a fairly good chance of success. Only thing I've found that refuses to boot from CF in a converter so far is my X40 (if anyone has any tips on that, please send them my way :-)
Re: RAMdisk, not for boot, how?
On Sat, 29 Mar 2008 13:29:41 -0400, Douglas A. Tutty wrote: I have my old IBM ValuePoint 486 that has a bios that really only likes drives under 512 MB. It has worked with one 8 GB drive, but not another seemingly identical WD 8 GB drive, yet alone a new-off-the-shelf 80 GB PATA drive. The IBM bios has no adjustability (as does the Award bios), but instead just displays the size of the hard drive found. If it displays a size, it will boot from it, if not, it declares a hardware error and won't boot from anything. I wonder if a 512 MB CF card in a PATA-CF adapter would be a solution in this case. The box would likely do remote-logging anyway. Does a CF card in a PATA-CF adapter look just like a HD, bootable and all, to old BIOS? The one I use does. Rod/ /earth: write failed, file system is full cp: /earth/creatures: No space left on device
RAMdisk, not for boot, how?
I don't know if this makes a lot of sense or any, but I was thinking that flash memory doesn't like too many writes. So I was thinking of creating one or two RAMdisks, for all those temporary reads and writes that I need, and only store the final result on the flash. The whole system will run from flash, true, but the directory with plenty of writes and processing should run in RAM. So I'd like to create a drive in RAM and then mount this drive as for the busy directory. Does this make sense? If yes, how to do it? Uwe
Re: RAMdisk, not for boot, how?
On 18:09:37 Mar 27, Uwe Dippel wrote: I don't know if this makes a lot of sense or any, but I was thinking that flash memory doesn't like too many writes. So I was thinking of creating one or two RAMdisks, for all those temporary reads and writes that I need, and only store the final result on the flash. The whole system will run from flash, true, but the directory with plenty of writes and processing should run in RAM. So I'd like to create a drive in RAM and then mount this drive as for the busy directory. Does this make sense? If yes, how to do it? You need memory file systems for that. It is very easy under OpenBSD. man mount_mfs You have examples in Andreas Bihlmaier's liveCD writeup here. http://openbsd-wiki.org/index.php?title=LiveCD You typically have to create a tar zip of the mount file system and untar it in the RAM disk and you are set. It is a good idea to mount /tmp and /var on RAM disks. -Girish
Re: RAMdisk, not for boot, how?
Speaking of RAMdisks, have you checked out Gigabyte i-RAM? Might be the right stuff for your need. On Thu, Mar 27, 2008 at 11:36 AM, Girish Venkatachalam [EMAIL PROTECTED] wrote: On 18:09:37 Mar 27, Uwe Dippel wrote: [snip] -Girish
Re: RAMdisk, not for boot, how?
On Thu, 27 Mar 2008 18:09:37 +0800, Uwe Dippel wrote: I don't know if this makes a lot of sense or any, but I was thinking that flash memory doesn't like too many writes. So I was thinking of creating one or two RAMdisks, for all those temporary reads and writes that I need, and only store the final result on the flash. The whole system will run from flash, true, but the directory with plenty of writes and processing should run in RAM. So I'd like to create a drive in RAM and then mount this drive as for the busy directory. Does this make sense? If yes, how to do it? Not really. The legend of CF wearing out should also be worn out by now for all practical purposes. When I first worked with the earliest nvram the life was very short (in write cycles) now I cannot deliberately wear out CF in any reasonable time. Running an OpenBSD firewall on a Soekris using Apacer 256MB CF I used the most verbose logging I could set up including for spamd handling 2 domains. After an install and two version installs (well over a year) I moved spamd onto the mailserver it protects but I'm still using the same old CF. If you want to be really really conservative buy a good brand, much larger than you need (= more spare cells) and replace it annually. Send your cast offs to any developer who would like to have them and he will get years of service out of most of them. Fiddle-arsing around doing fancy installs and using up limited RAM to be pretend disks ain't worth the effort. Generic installs Just Work (TM) and I've never lost a CF on client machines either and some of those are really busy little firewalls handling roadwarrior VPNs for a financial services company of considerable repute. The CF wearout meme needs to die. On-list replies will suffice. Private replies only to the reply-to: thanks. Uwe Rod/ /earth: write failed, file system is full cp: /earth/creatures: No space left on device
Re: RAMdisk, not for boot, how?
On 3/28/08 1:20 AM, Rod Whitworth wrote: The CF wearout meme needs to die. Specs, it's all about specs, it seems a fact to me that standard CF cards, as used in camera's, often without any technical specification other than size, cannot be written as often as ordinary harddisks. The foreseeable future people need to be really careful while choosing memory cards as hard disk replacements. +++chefren
Re: RAMdisk, not for boot, how?
On Fri, 28 Mar 2008 02:51:33 +0100, chefren wrote: On 3/28/08 1:20 AM, Rod Whitworth wrote: The CF wearout meme needs to die. Specs, it's all about specs, it seems a fact to me that standard CF cards, as used in camera's, often without any technical specification other than size, cannot be written as often as ordinary harddisks. The Apacer cards I use are PhotoSteno III made for camera use and I cannot kill one. Maybe you can wear one out in several years but you will never have a head crash or motor failure. SanDisk gives a five year warranty with no mention of write cycle limitations and I did see a data sheet somewhere that showed you could shoot a CF full of pix every day and erase them every night for 27 years and still not reach the write cycle limit. I cannot remember what brand that was. I have lost cout of failed HDDs around here and never lost a byte on CF. There are nearly as many CFs here as HDDs now and if you have a look at new laptops you'll see more and more SSHD and hybrids every time a new model comes out. Practically speaking if you buy a decent brand of CF or spend the extra on an industrial model you can expect years of service out of it. I'm sure that Bamboo Charlie makes cheapies in CF as well as mobos and other junk, don't buy from him The foreseeable future people need to be really careful while choosing memory cards as hard disk replacements. Bought any Seagate drives lately? ;) +++chefren Rod/ /earth: write failed, file system is full cp: /earth/creatures: No space left on device
Re: RAMdisk, not for boot, how?
chefren wrote: On 3/28/08 1:20 AM, Rod Whitworth wrote: The CF wearout meme needs to die. Specs, it's all about specs, it seems a fact to me that standard CF cards, as used in camera's, often without any technical specification other than size, cannot be written as often as ordinary harddisks. maybe, maybe not. Rod's right, though... I've never seen a flash media die from write fatigue. I have seen and heard of a fair number die for other reasons. There are reasons to use flash media. Reliability is not one of them in my mind. They are small, they are quiet, they are low power, they are vibration resistant. They last a long time...usually. But they can fail. The foreseeable future people need to be really careful while choosing memory cards as hard disk replacements. I agree, but not for the reasons usually given. If you are using a flash drive to avoid worrying about failures, you are fooling yourself..even if the flash drives were PERFECT, there are other parts of the computer that fail, and there are user errors. SO, you still need the EXACT SAME recovery processes in place for flash drives as you do for disks. Using flash doesn't let you dodge recovery and backup needs. If you try to shoe-horn a big system into a small flash drive and make something you don't properly maintain (key issue is DO YOU maintain it, not COULD you maintain it. Doesn't matter what you could do if you don't), the system will be less reliable. If you have an app where you need or want low power, quiet or small, go ahead, use flash media, but for goodness sake, don't screw up a really good OS by trying to meet some goal that is completely bogus. Just use it as normal, and maintain it as normal. Odds are, something else will take your system down long before write fatigue does, most likely, it will be your butchery of a working solution. It's the unexpected downtime that counts, not the reason. Who the frick cares that you tried to avoid a one-in-five-year hypothetical failure if you caused several days of very non-hypothetical downtime as a result? A simple, standard install will out-perform your hacked up mess every time. Someone posted an article recently about people liking to use Linux because they like tweaking and adjusting and working with the system. I've worked with people like that -- they are smart and clever and will cause hours of downtime to avoid a totally non-problem (or on really cool technology. This don't write to flash is a perfect example. If you wish to set a goal for yourself of I don't wish to ever write to this disk, great. BUT don't tell yourself or anyone else this frankensystem is better than the normal installation. So, if your goal is a reliable system, keep it simple. If your goal is to have fun, do so. But don't confuse having fun with doing good work. Yes, you learn more by breaking things, but you impress people more if you break 'em off-line, and use that knowledge to keep your production stuff running and repaired quickly when it breaks. Nick.
