Documentation
Where is the best documentation on raid in general located? I'm thinking about striping my drives (raid 0 -- 2 IDE and 1 scsi) but have no idea what I'm up against, or if it would benefit me on speed. I looked through HOWTO's but found only the ROOT-RAID howto. It seems to deal with older raid drivers, and I don't plan to put my root on a MDx anyway. I want to reformat my drives to keep roughly the same partition sizes I have now, but with increased speed from spreading the data across multiple drives. Am I way off base? Gerald -- '69 Bug (Airball, the Rolling Basket Case) Have a look at my online store for gift ideas: a HREF="http://shop.affinia.com/phorce1/Store/"/a
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Re: Documentation
On Wed, 29 Mar 2000 [EMAIL PROTECTED] wrote: Where is the best documentation on raid in general located? I'm thinking about striping my drives (raid 0 -- 2 IDE and 1 scsi) but have no idea what I'm up against, or if it would benefit me on speed. I looked through HOWTO's but found only the ROOT-RAID howto. It seems to deal with older raid drivers, and I don't plan to put my root on a MDx anyway. With raid0 you will benefit speedwise, but will lose what comes to reliability. The fault on one drive will propably rend your whole raid0 array useless. I want to reformat my drives to keep roughly the same partition sizes I have now, but with increased speed from spreading the data across multiple drives. Am I way off base? You are in correct base :) First take a look at, or preferrably read it through with thought http://www.linuxdoc.org/HOWTO/Software-RAID-HOWTO.html Then you might want to get linux 2.2.14 and patch it with: http://people.redhat.com/mingo/raid-patches/raid-2.2.14-B1 Also get and compile this for userland tools: http://people.redhat.com/mingo/raid-patches/raidtools-dangerous-0.90-2116.tar.gz and you should be ready to go. -- Mika [EMAIL PROTECTED]
Raid 1 Mirror (the second try)
Hello Because of my problems in sending mails yesterday here is my second mail once again. ---begin--- Hello again :o) The old HOWTOs are up to date with the old code. But the old code is _old_ (and buggy etc.) Yes, but they discribe that you must patch the 2.0.x kernel. And this needn´t be done with the actual 2.2.13 kernel. (If s.o. want to use the old system) But I have seen your name in the new RAID-HowTo, so no further questions about the old system :-) My question is now: shall I take the normal kernel-buildin RAID System (with the mdtools) or shall I patch my 2.2.13 kernel (SuSE-Linux Distribution) and use the new one (with the raidtools)? Patch 2.2.15pre15 instead. It's more stable than 2.2.13. Uh. Is the 2.2.15pre15 a newer kernel or a patch? Where can I get it? The new one is much easier I think. Yep. I had a night-mare after reading the boot-howto... :-) But is it really stable enough for a normal RAID 1 System with two IDE-Disks? There is a /boot Partition (now RAID) and a / , /home and /db-Partition on each Disk which I want to mirror. RAID-1 is in my experience very stable with IDE disks. Is it only needful to give every disk its own controller or is it neccecary? Patch for 2.2.14 at http://people.redhat.com/mingo applies fairly well to 2.2.15pre15 too, with one (easy) reject in raid1.c which you will have to fix by hand. Aha! You mean that I can take the 2.2.15pre15 kernel (because it is more stable) and use the 2.2.14 patch from RedHat. Is this right? What do you mean with reject in raid1.c? Is this a message which appears, when I patch the kernel? How can I fix by hand? Will I see, how it can be fixed? Thanks, Andreas -- Andreas Martmann Institut für Geoinformatik (IfGI) Robert-Koch-Str. 26-28 48149 Münster E-Mail : [EMAIL PROTECTED] Homepage : http://ifgi.uni-muenster.de
Re: Raid-Related System Locks
I am no RAID expert, but I know a SCSI bus hang when I see one. A suggestions which I am sure everyone will make: 1. Try the 2.2.14 kernel with the newer patch: http://people.redhat.com/mingo/raid-patches/raid-2.2.14-B1 And a few of my own: 2. Try booting with kernel argument "aic7xxx=verbose" and see of you get any more interesting messages. 3. The reason your log stops is because your SCSI bus stops. If you have another machine running syslogd, try pointing your log across the network; see the section about "Remote Machine" in the "man syslog.conf" page. 4. Unplug the Plextor. -- Mike On Tue, 28 Mar 2000, Bernd Burgstaller wrote: Dear all! I am writing this mail due to hangups related to my raid devices. I am seeking for suggestions enabling me to locate the problem. Any suggestions are welcome! Below you find a description of my system as well as of the problems. If you need further information, please let me know. Best regards thanks in advance, Bernd Burgstaller
re: aic7xxx, SMP, providence board
On Tue, 28 Mar 2000, Edward Schernau wrote: How do you get interrupts 17 and 18 ??? -- Edward Schernau http://www.schernau.com Network Architect mailto:[EMAIL PROTECTED] Rational ComputingProvidence, RI, USA That is a feature of IO-APIC. Hi, Neighbor! -- Mike -- --- Bilow Computer Science, Inc. | http://www.bilow.com/ | Michael S. Bilow Cranston, RI 02920-5554, USA | [EMAIL PROTECTED]| President --- PGP Public Key fingerprint = 4B 06 23 FB 3E 24 A5 24 14 B5 A2 14 96 73 B4 B2 PGP Public Key fingerprint = A5 13 63 7F E3 9F AB 0A 52 62 49 26 BF 0C 01 AD ---
Which IDE controller
Hello, I'm setting up a box with 8 IDE disks, and I need a secondary controller that can be used in addition to the onboard one. It's gotta be cheap, too. What's the best solution on a ca. $80 budget? Can any of these controllers work with more controllers (like 2 controllers + internal = 12 IDE disks)? I've already looked at the hardware IDE raid boxes, too expensive for this home test project. Thanks in advance for any tips! O/T Question: Does anyone know any programs for Linux to change the byte order of a windows binary file? We've got a small self-developed "database" in a binary file, and we need to read info from it using Linux. Have a nice day! Kent R. Nilsen
Re: Which IDE controller
The promise cards are nice. You can buy the cheap ata/66 ones and add one resistor to convert them into their fastrack hardware RAID controller. See: http://www.geocities.com/promise_raid/english.htm The cards only cost about $25 on pricewatch.com. So you can get two hardware RAID IDE controllers for $60-70 all in. Cheers, Chris - Original Message - From: "Kent Nilsen" [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Wednesday, March 29, 2000 11:07 AM Subject: Which IDE controller Hello, I'm setting up a box with 8 IDE disks, and I need a secondary controller that can be used in addition to the onboard one. It's gotta be cheap, too. What's the best solution on a ca. $80 budget? Can any of these controllers work with more controllers (like 2 controllers + internal = 12 IDE disks)? I've already looked at the hardware IDE raid boxes, too expensive for this home test project. Thanks in advance for any tips! O/T Question: Does anyone know any programs for Linux to change the byte order of a windows binary file? We've got a small self-developed "database" in a binary file, and we need to read info from it using Linux. Have a nice day! Kent R. Nilsen
Re: Raid1 - dangerous resync after power-failure?
I hope you're making a joke. that's not a joke - i found it in a document describing raid. I hope I can find it again, so I can send it to you! The problem is that I'm trying to use the software in the "real world" where the most likely need for raid-1 is due to power problems. Therefore you should use UPS. not raid. And even when you are using a journalling file-system it's possible to lose data. At least that's been my experience over many years of doing sysadmin - most disk failures seem to occur after some sort of power outage. Either the power goes out, or somone accidentally pulls the plug, etc. I had a server running a raid5 with 3 disks and after some power failures the system didn't want to mount the disk again. The other - un-raided disks didn't have any problem. - After reinstallation and adding a UPS all is fine (now for 8 months). Sam Thomas Kotzian wrote: raid wasn't invented to survive a power failure but a disk-failure! Thomas - Original Message - From: "Sam" [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, March 27, 2000 1:00 PM Subject: Raid1 - dangerous resync after power-failure? I'm setting up a web server with Raid-1, using raidtools 0.90-5 and linux kernel 2.2.12 (this is the Redhat 6.1 distr). I want to mirror all my data across two disks (hda and hdc). The problem I've noticed from testing is that if I shut off the power and then reboot, the raidtools software will start re-syncing the mirrors, even though there was no write activity at all when the power went off and even though both parts of the mirror have the exact same event counter. The problem I see with this is as follows: - Assume a power outage hits and wipes out some sectors on the hda disk, but leaves the superblock alone. I think this scenario is a fairly likely one. - After the power outage, the system boots up and starts up a resync, copying data from hda to hdc - The system tries to access the bad sectors on hda What would happen at this point? I assume the data would be lost, since hdc is undergoing a re-sync, and the sectors on hda are already bad. Even though at boot time hdc contained good copies of these sectors, the raid software starting re-syncing onto hdc and lost that data. If however the raid code had just left hdc alone it could've recovered these sectors. I looked at the raidtools code, and it looks to me what is happening is that there is a SB_CLEAN flag in the superblock that is set to false when raid is started on an md device. This SB_CLEAN flag is only set to true if a clean shutdown is performed. So if a power outage hits, this flag is always going to be false since no clean shutdown is performed. At boot time the md code then checks the SB_CLEAN flag and if it is false a resync is performed. It seems to me that a resync should only be required if the system is in the middle of a write where some data has been sent to one disk, but not yet to another. I think the event counter already performs this function so I don't see why the SB_CLEAN flag is even needed. What do you think? Could this SB_CLEAN flag be eliminated to reduce the risk of a resync damaging good data?
Kernel 2.2.14 vs 2.2.15pre15
-BEGIN PGP SIGNED MESSAGE- Hi, Jakob! Are there any drawbacks with kernel 2.2.14? Patch 2.2.15pre15 instead. It's more stable than 2.2.13. Ciao' Harry - -- Harald Groene Tel +49 2389 2965 Ostenhellweg 49 Fax +49 2389 2969 D-59192 Bergkamen mailto:[EMAIL PROTECTED] -BEGIN PGP SIGNATURE- Version: 2.6.3i Charset: noconv iQCVAwUBOOJF8ct5E9tvgtZxAQHAugQAjdCtriQ/Y86/Xovp++5DneP1scE9AR6n 4PlePiqxGA043vlfYDgsmbtDBK8Nm8wtd7A1LalR87DOzToyWOGmNJlTwO3RITMy vnZXRHGipn64TARBNc3lrGfkq7sSmY0qr+rrqsKkpoaT4MXg94R0e1AkdnDTXspR 3VqsvJGJuc0= =EDrN -END PGP SIGNATURE-
raid 1
Dear Friend, I'm trying to do a RAID level 1 on my Linux server, but I have some problems, if you can give me a tip, I will stay happy: Environment: Linux Kernel 2.2.12 (Red Hat 6) Server with 2 disks and 2 SCSI controlers, with 8Gb each. Devices /dev/sda5 and /dev/sdb5 the file /etc/raidtab contains the follow raiddev/dev/md0 raid-level 1 nr-raid-disks2 nr-spare-disks 0 device /dev/sda5 raid-disk0 device /dev/sdb5 raid-disk1 then, when I run the command * MKRAID /dev/md0 handling MD device /dev/md0 analyzing super-block invalid chunk-size (0kb) mkraid: aborted and the command * RAIDSTART --all md: can not import sda, has active inotes! could not import sda5! autostart sda5 failed! /dev/md0: invalid argument do you know where I can find a good documentation lika a "HOW TO" to make the Mirror (RAID1) special thanks Leandro Lacalle Turbino Lintec Integrated Solutions Fone # +55+11 7690-1666
probably an unrecoverable SCSI bus on dual CPU
Hi, I got a dual intel with SCSI-2 mother card (adaptec 78XX) with a single SCSI-2 at the moment. I have tried bonnie tio on a single CPU (CM dual capable) and it worked fine Now, I added a CPU (2XPIII500) and recompiled kernel. Bonnie worked fine but tiobench gives me: SCSI bus is being reset for host 0 chanel 0 SCSI host 0 chanel 0 reset (pid 27465) timed out probably an unrecoverable SCSI bus SCSI bus is being reset for host 0 chanel 0 SCSI host 0 chanel 0 reset (pid 27465) timed out probably an unrecoverable SCSI bus ... no keyboard, no network, all is down :( have you any idea ? PS I have not even tried raid :( thanks Octave
RE: ext2resize
-Original Message- From: Seth Vidal [mailto:[EMAIL PROTECTED]] Sent: Wednesday, March 29, 2000 11:33 AM To: [EMAIL PROTECTED] Subject: ext2resize hi folks, ext2resize claims to be able resize ext2 partitions w/o destroying data. While there is evidence of this on normal drives and hw raid drives too. I'd like to know if it will work on sw raid drives. Seems to me that this would only work if you were using it with the Logical Volume Manager (is that what it's called?). I think that the RAID devices are treated as a partition, not as a whole disk, so it wouldn't work that way. I don't know enough about LVM to know if that would work either. Greg
RE: raid 1
-Original Message- From: Leandro Lacalle Turbino [mailto:[EMAIL PROTECTED]] Sent: Wednesday, March 29, 2000 10:31 AM To: [EMAIL PROTECTED] Cc: Alfredo Junior Subject: raid 1 Dear Friend, I'm trying to do a RAID level 1 on my Linux server, but I have some problems, if you can give me a tip, I will stay happy: Environment: Linux Kernel 2.2.12 (Red Hat 6) Server with 2 disks and 2 SCSI controlers, with 8Gb each. Devices /dev/sda5 and /dev/sdb5 the file /etc/raidtab contains the follow raiddev/dev/md0 raid-level 1 nr-raid-disks2 nr-spare-disks 0 device /dev/sda5 raid-disk0 device /dev/sdb5 raid-disk1 then, when I run the command * MKRAID /dev/md0 handling MD device /dev/md0 analyzing super-block invalid chunk-size (0kb) mkraid: aborted Well, this messsage says that the chunk-size that you didn't specify is invalid. Try specifying a chunk-size in raidtab. Greg
Re: ext2resize
I would 'hope' it would work. (under the assumption that raid is only concerned with portraying a block device without concern for what is stored on that block device) Of course, that's just a 'hope'. :) On Wed, 29 Mar 2000, Seth Vidal wrote: -hi folks, - ext2resize claims to be able resize ext2 partitions w/o destroying data. -While there is evidence of this on normal drives and hw raid drives too. -I'd like to know if it will work on sw raid drives. - -anyone know? - -thanks - --sv - -
Re: ext2resize
ext2resize claims to be able resize ext2 partitions w/o destroying data. What's more, it does ... While there is evidence of this on normal drives and hw raid drives too. (I assume the `While' is spurious). I have first hand evidence of the first. I'd like to know if it will work on sw raid drives. It's independent of the underlying hardware -- ext2 just sees a set of disk blocks -- it does not care what type they are! (actually, it's best to use it on top of LVM) anyone know? I have used it on SW RAID.
Re: ext2resize
What's more, it does ... While there is evidence of this on normal drives and hw raid drives too. (I assume the `While' is spurious). I have first hand evidence of the first. I'd like to know if it will work on sw raid drives. It's independent of the underlying hardware -- ext2 just sees a set of disk blocks -- it does not care what type they are! (actually, it's best to use it on top of LVM) anyone know? I have used it on SW RAID. Just felt like I should ask first - it makes me uneasy expanding the drive - how would you go about doing this with sw raid - like how would I do it if I wanted to add a drive to the array? this might be useful to add to the howto. -sv
Re: Raid1 - dangerous resync after power-failure?
OK, regardless of how the failure occurs, my point is that a resync is a potentially dangerous operation if you don't know beforehand whether the source disk has bad sectors or not. So I don't think a resync should be performed except when absolutely necessary, or unless the source disk is known to be absolutely free from errors. Can someone answer my original question which was: Could the SB_CLEAN flag be eliminated to reduce the risk of a resync damaging good data? I hope you're making a joke. that's not a joke - i found it in a document describing raid. I hope I can find it again, so I can send it to you! The problem is that I'm trying to use the software in the "real world" where the most likely need for raid-1 is due to power problems. Therefore you should use UPS. not raid. And even when you are using a journalling file-system it's possible to lose data. At least that's been my experience over many years of doing sysadmin - most disk failures seem to occur after some sort of power outage. Either the power goes out, or somone accidentally pulls the plug, etc. I had a server running a raid5 with 3 disks and after some power failures the system didn't want to mount the disk again. The other - un-raided disks didn't have any problem. - After reinstallation and adding a UPS all is fine (now for 8 months). Sam Thomas Kotzian wrote: raid wasn't invented to survive a power failure but a disk-failure! Thomas - Original Message - From: "Sam" [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, March 27, 2000 1:00 PM Subject: Raid1 - dangerous resync after power-failure? I'm setting up a web server with Raid-1, using raidtools 0.90-5 and linux kernel 2.2.12 (this is the Redhat 6.1 distr). I want to mirror all my data across two disks (hda and hdc). The problem I've noticed from testing is that if I shut off the power and then reboot, the raidtools software will start re-syncing the mirrors, even though there was no write activity at all when the power went off and even though both parts of the mirror have the exact same event counter. The problem I see with this is as follows: - Assume a power outage hits and wipes out some sectors on the hda disk, but leaves the superblock alone. I think this scenario is a fairly likely one. - After the power outage, the system boots up and starts up a resync, copying data from hda to hdc - The system tries to access the bad sectors on hda What would happen at this point? I assume the data would be lost, since hdc is undergoing a re-sync, and the sectors on hda are already bad. Even though at boot time hdc contained good copies of these sectors, the raid software starting re-syncing onto hdc and lost that data. If however the raid code had just left hdc alone it could've recovered these sectors. I looked at the raidtools code, and it looks to me what is happening is that there is a SB_CLEAN flag in the superblock that is set to false when raid is started on an md device. This SB_CLEAN flag is only set to true if a clean shutdown is performed. So if a power outage hits, this flag is always going to be false since no clean shutdown is performed. At boot time the md code then checks the SB_CLEAN flag and if it is false a resync is performed. It seems to me that a resync should only be required if the system is in the middle of a write where some data has been sent to one disk, but not yet to another. I think the event counter already performs this function so I don't see why the SB_CLEAN flag is even needed. What do you think? Could this SB_CLEAN flag be eliminated to reduce the risk of a resync damaging good data?
Re: Promise ATA66
On Sun, 26 Mar 2000, Dan Hollis wrote: On Sun, 26 Mar 2000, flag wrote: Aybody out there is using this controller? Yes Do you have the 2.3.* kernel or had applied any patch to 2.2.*? Anybody is using its hardware raid capabilities? no But it's supported or no these feature?!?!? Thanks. Paolo
Re: ext2resize
On Wed, Mar 29, 2000 at 03:49:17PM -0500, David Holl wrote: I would 'hope' it would work. (under the assumption that raid is only concerned with portraying a block device without concern for what is stored on that block device) Of course, that's just a 'hope'. :) Unfortunately, with the RAID superblock at the back of each RAID partition, you're going to need a tool that understands that it's there. I remember seeing someone posting about a RAID resizer which calls the resize2fs package. Don't know where that went, but that's probably what you want. -- Randomly Generated Tagline: "... by changing many lightbulbs, and I'm an Electrical Engineer, and it only takes 1 of us ..." - Prof. Vaz
Re: Promise ATA66
On Wed, 29 Mar 2000, flag wrote: On Sun, 26 Mar 2000, Dan Hollis wrote: On Sun, 26 Mar 2000, flag wrote: Aybody out there is using this controller? Yes Do you have the 2.3.* kernel or had applied any patch to 2.2.*? Applied patch to 2.2.x try www.kernel.dk Anybody is using its hardware raid capabilities? no But it's supported or no these feature?!?!? it's software raid with a little hardware assistance (i think) -Dan
Re: ext2resize
What you *REALLY* want is LVM url please? pointers of some type? -sv
Re: ext2resize
What you *REALLY* want is LVM url please? Sorry -- I assumed RAID users would all know about http://linux.msede.com/lvm/ Mirror sites The following ftp sites are known to mirror the LVM tree: ftp://ftp.gwdg.de/pub/linux/misc/lvm/ (daily mirror, thanks to Eberhard Moenkeberg) ftp://source.rfc822.org/pub/mirror/LVM/ (daily mirror, thanks to Richard Higson) ftp://linux.mathematik.tu-darmstadt.de/pub/linux/mirrors/misc/lvm/ (daily mirror, thanks to Holger Grothe) ftp://ftp2.sinica.edu.tw/pub1/lvm (Taiwan)
Re: ext2resize
What you *REALLY* want is LVM On the subject of LVM... I'm getting ready to setup a storage server for raw video using 3ware (www.3ware.com) IDE HW raid and 6 40gig ide drives. Speed isn't as much as issue as raw volume of storage. I was looking at LVM and wondering what advantage it would give me. I like the idea of the volume groups and logical volumes but what does LVM give me other than the ability to resize/change volumes?
Re: ext2resize
I would think that a block device is a block device from the point of view of software like this, so I cannot see any reason to expect a block device created by software RAID to look any different to it. That said, I have never tried it, so take my advice with a grain of salt. -- Mike On Wed, 29 Mar 2000, Seth Vidal wrote: hi folks, ext2resize claims to be able resize ext2 partitions w/o destroying data. While there is evidence of this on normal drives and hw raid drives too. I'd like to know if it will work on sw raid drives. anyone know? thanks
Promise ATA66
No, it seems that it DOES do hw RAID, but with no battery backup, onboard RAM, etc.
Re: ext2resize
On the subject of LVM... I'm getting ready to setup a storage server for raw video using 3ware (www.3ware.com) IDE HW raid and 6 40gig ide drives. Speed isn't as much as issue as raw volume of storage. I was looking at LVM and wondering what advantage it would give me. I like the idea of the volume groups and logical volumes but what does LVM give me other than the ability to resize/change volumes? LVM is very nice if you need more than 1 partition on your RAID storage. YOu then just create one large RAID set, and partition it with LVM, its really very handy. Also LVM could even combine more one one physical storage into a Volume Group. Of course you could do that with RAID too, but with LVM you could do it after you´ve created you´re filesystems. E.g you buy today a 100 GB Raid for you´re videoservice, and next year add a second RAID set with for example 1 TB. LVM would allow you to combine both RAID sets into on Logical Volume. Of course this needs a working ext2resize. And of course I would not recommend such a large Logical Volume without an Journaling Filesystem. Sincerely, Klaus -- Klaus Steinberger Beschleunigerlabor der TU und LMU Muenchen Phone: (+49 89)289 14287Hochschulgelaende, D-85748 Garching, Germany FAX: (+49 89)289 14280EMail: [EMAIL PROTECTED] URL: http://www.bl.physik.tu-muenchen.de/~k2/ Stimm gegen Spam: http://www.politik-digital.de/spam/ In a world without fences and walls, who needs Windows and Gates?
