Re: RAID questions
On Mon, 7 Aug 2000, Adam McKenna wrote: 2) If I do, will it still broken unless I apply the "2.2.16combo" patch? 3) If it will, then how do I resolve the problem with the md.c hunk failing with "2.2.16combo"? If I remember correctly, 2.2.16combo was there to make it possible to use Ingo's older raid patches on 2.2.16 (before raid-2.2.16-A0 was released). I'm not 100% sure, though. This is a production system I am working on here. I can't afford to have it down for an hour or two to test a new kernel. I'd rather not be working with this mess to begin with, but unfortunately this box was purchased before I started this job, and whoever ordered it decided that software raid was "Good enough". A test machine comes in handy. Not to actually test the new RAID code (we did/do that already ;) ), but just to train handling of SW raid. I am not subscribed to either list so CC's are desirable. However if you don't want to CC then you don't have to -- I'll just read the archives. That is, if someone fixes the "Mailing list archives" link on www.linux.org to point to someplace that exists and actually has archives. IMHO, if you need (or want) to work with SW raid, it would be better to subscribe. It's not all that much traffic here and (usually) the stuff we get here is relevant (with exception of too many questions on patches location, but that should be fixed anyway). Besides, any real problems, bug reports, warnings appear here very soon. D.
Re: RAID questions
On Mon, Aug 07, 2000 at 08:07:58PM -0700, Gregory Leblanc wrote: I'm a little verbose, but this should answer most of your questions, although sometimes in a slightly annoyed tone. Don't take it personally. There's a difference between being annoyed and being immature. You seem to have answered everything with maturity, so no offense taken. Hello, I consider the current state of affairs with Software-RAID to be unbelievable. It's not as bad as you think. :-) Maybe not to someone who follows the list regularly, but for someone who needs to get things accomplished, it's pretty bad. 1) The current RAID-Howto (on www.linux.org) does not indicate the correct location of RAID patches. I had to go searching all over the web to find the 2.2.16 RAID patch. Did you try reading the archives for the Linux-RAID list? I've started on a FAQ that will be updated at very least monthly, and posted to linux-raid. I did a search on google. The majority of posts I was able to find mentioned a 2.2.15 patch which could be applied to 2.2.16 as long as several hunks were hand-patched. Personally, I don't particularly like hand-patching code. Especially when the data that my job depends on is involved. 2) The current 2.2.16 errata lists a problem with md.c which is fixed by the patch "2.2.16combo". I believe that md software RAID applies to the old RAID code. The RAID stuff has been VERY good for quite a while now. The howto on linux.org listed ftp://www.fi.kernel.org/pub/linux/daemons/raid as the "official" location for the RAID patches. The patches located there only went up to 2.2.11. In fact, looking now, the linuxdoc.org howto lists the same location. 3) The patch "2.2.16combo" FAILS if the RAID patch has already been applied. Ditto with the RAID patches to md.c if the 2.2.16combo patch has already been applied. Perhaps they're not compatible, or perhaps one includes the other? Have you looked at the patches to try to figure out why they don't work? I'm NOT a hacker, but I can certainly try to figure out why patches don't work. I looked at them. It appears as though the RAID patch changes the relevant section to something totally different than it was before, so that the patch can't be applied, even with an offset. This is why I asked the question in the first place. In retrospect, I suppose it was a stupid question, but I'd rather be safe than sorry. 4) The kernel help for all of the MD drivers lists a nonexistant Software-RAID mini-howto, which is supposedly located at ftp://metalab.unc.edu/pub/Linux/docs/HOWTO/mini. There is no such document at this location. There are 2 Software-RAID HOWTOs available there, although they are 1 directory higher than that URL. For the code included in the stock kernels, see ftp://metalab.unc.edu/pub/Linux/docs/HOWTO/Software-RAID-0.4x-HOWTO. For the new RAID code by Ingo and others, see ftp://metalab.unc.edu/pub/Linux/docs/HOWTO/Software-RAID-HOWTO. Both of these documents are easily available from http://www.LinuxDoc.org/ Thanks for the link. However as mentioned above the howto there still gives the incorrect location for current kernel patches. 5) The kernel help also does not make it clear that you even need a RAID patch with current kernels. It is implied that if you "Say Y here" then your kernel will support RAID. This problem is exacerbated by the missing RAID patches at the location specified in the actual Software-RAID-Howto. No, you don't NEED to patch your kernel to get RAID (md raid, that is) working. You DO need to patch the kernel if you want the new RAID code. Everyone on the Linux-RAID list will recommend the new code, I don't know about anybody else. So, I have the following questions. 1) Do I need to apply the RAID patch to 2.2.16 or not? Do you want new RAID, or old RAID? Well, the box won't boot with the stock MD driver. 2) If I do, will it still broken unless I apply the "2.2.16combo" patch? If you apply the combo patch, that will fix things with the old code (I think, have not verified this yet). If you apply the RAID patch (from the location above), then you don't need to worry about the fixes in the 2.2.16combo. 3) If it will, then how do I resolve the problem with the md.c hunk failing with "2.2.16combo"? Apply manually? Just take a look at the .rej files (from /usr/src/linux do a 'find . -name "*rej*"') and see what failed to apply. I generally open a split pane editor, (for emacs, just put two file names on the command line), and see if I can find where the patch failed, and try to add the missing/remove the extraneous lines by hand. It's worked so far. See above. 4) Is there someone I can contact who can update publically available documentation to make it easier for people to find what they're looking
RE: Root Raid Questions....
Hi, this is my /var/log/messages it doesn't start MD0, Why ? At this moment 'm using kernel 2.2.13ac12 with last raidtools, what's wrong ? Best Regards, Luca Pescatore Sep 27 15:26:36 test kernel: Detected scsi disk sdb at scsi0, channel 0, id 1, l un 0 Sep 27 15:26:36 test kernel: SCSI device sda: hdwr sector= 512 bytes. Sectors= 1 7916240 [8748 MB] [8.7 GB] Sep 27 15:26:36 test kernel: sda: sda1 sda2 sda3 sda4 Sep 27 15:26:36 test kernel: SCSI device sdb: hdwr sector= 512 bytes. Sectors= 1 7916240 [8748 MB] [8.7 GB] Sep 27 15:26:36 test kernel: sdb: sdb1 sdb2 sdb3 sdb4 Sep 27 15:26:36 test kernel: autodetecting RAID arrays Sep 27 15:26:36 test kernel: (read) sda2's sb offset: 7992256 [events: 000a] Sep 27 15:26:36 test kernel: (read) sdb2's sb offset: 7992256 [events: 000a] Sep 27 15:26:36 test kernel: autorun ... Sep 27 15:26:36 test kernel: considering sdb2 ... Sep 27 15:26:36 test kernel: adding sdb2 ... Sep 27 15:26:36 test kernel: adding sda2 ... Sep 27 15:26:36 test kernel: created md0 Sep 27 15:26:36 test kernel: bindsda2,1 Sep 27 15:26:36 test kernel: bindsdb2,2 Sep 27 15:26:36 test kernel: running: sdb2sda2 Sep 27 15:26:36 test kernel: now! Sep 27 15:26:36 test kernel: sdb2's event counter: 000a Sep 27 15:26:36 test kernel: sda2's event counter: 000a Sep 27 15:26:36 test kernel: kmod: failed to exec /sbin/modprobe -s -k md- person ality-3, errno = 2 Sep 27 15:26:36 test kernel: do_md_run() returned -22 Sep 27 15:26:36 test kernel: unbindsdb2,1 Sep 27 15:26:36 test kernel: export_rdev(sdb2) Sep 27 15:26:36 test kernel: unbindsda2,0 Sep 27 15:26:36 test kernel: export_rdev(sda2) Sep 27 15:26:36 test kernel: md0 stopped. Sep 27 15:26:36 test kernel: ... autorun DONE.
Re: Root Raid Questions....
You don't have to put lilo on the boot partitions. It can go on the MBR. Lilo needs to point to files on a non-raided partition, not necessarily be on that partition itself. Sorry, on the MBR is what I meant... The following /etc/lilo.conf should work for /dev/sda (substituting appropriate device and file names for things such as /boot/vmlinuz and /dev/md0): boot=/dev/sda map=/boot/map install=/boot/boot.b prompt timeout=50 image=/boot/vmlinuz label=linux root=/dev/md0 read-only You will want an alternative lilo.conf for booting from /dev/sdb if /dev/sda fails. Let's call the alternative lilo.conf /etc/lilo.conf/sdb. Assuming your copy of the boot partition on /dev/sdb is mounted on /bootb/, it wants to look something like: boot=/dev/sdb disk=/dev/sdb bios=0x800 The line above is what I missed THANKS!!! map=/bootb/map install=/bootb/boot.b prompt timeout=50 image=/bootb/vmlinuz label=linux root=/dev/md0 read-only The second line is the significant one. It tells lilo that although we are currently referring to this disk as /dev/sdb, when it comes to booting, it will be at /dev/sda's bios location (0x800). You can install this to /dev/sdb by running "lilo -C /etc/lilo.conf.sdb". This will give you cover against /dev/sda failing so catastrophically that it is not recognized at reboot. But it does not cover you against the situation where /dev/sda's MBR gets corrupted, or any other situation where /dev/sda continues to be recognized but cannot boot. You will want to keep a boot floppy handy for these circumstances. Alternatively, we could just pull /dev/sda and reboot -- Bo Kersey email: [EMAIL PROTECTED] virCIO - managed server solutions phone: (512)374-0500 4314 Avenue Cfax: (512)377-3336 Austin, TX 78751-3709 Start your own revolution and cut out the middle man. -Billy Bragg PGP signature
Boot Linear/RAID-1 [was: Root Raid Questions....]
If we don't already have a HOWTO section on this issue, we probably should add one. We've seen more and more questions on this topic of late... Just my half-nybble. On a similar note, wouldn't it be possible to boot from RAID-1/5 using a similar method if the chunk size was greater than the kernel size? Obviously this would be a big chunk size, and only particularly useful for systems serving big files. -- Jeremy Stanley Trend CMHS Network Engineer http://www.trendcmhs.org The opinions expressed herein do not necessarily represent those of Trend CMHS or Trend Foundation. "I program my homecomputer; beam myself into the future." --Kraftwerk, 1981
RE: Boot Linear/RAID-1 [was: Root Raid Questions....]
-- From: Stanley, Jeremy Sent: Monday, September 27, 1999 12:00 PM To: Linux-Raid Subject: Boot Linear/RAID-1 [was: Root Raid Questions] [clip] On a similar note, wouldn't it be possible to boot from RAID-1/5 using a similar method if [snip] Correction. I meant "RAID-0 or RAID-5." Fat fingers today. -- Jeremy Stanley Trend CMHS Network Engineer http://www.trendcmhs.org The opinions expressed herein do not necessarily represent those of Trend CMHS or Trend Foundation. "I program my homecomputer; beam myself into the future." --Kraftwerk, 1981
Re: Boot Linear/RAID-1 [was: Root Raid Questions....]
At 12:00 PM 9/27/1999 -0400, Stanley, Jeremy wrote: If we don't already have a HOWTO section on this issue, we probably should add one. We've seen more and more questions on this topic of late... Just my half-nybble. On a similar note, wouldn't it be possible to boot from RAID-1/5 using a similar method if the chunk size was greater than the kernel size? Obviously this would be a big chunk size, and only particularly useful for systems serving big files. It sounds feasable, but you'd lose the benefits of raid if one file was in one chunk... that drive goes and any files smaller than one chunk on that drive are history === David Cooley N5XMT Internet: [EMAIL PROTECTED] Packet: N5XMT@KQ4LO.#INT.NC.USA.NA T.A.P.R. Member #7068 We are Borg... Prepare to be assimilated! ===
Re: Raid Questions
On Thu, 16 Sep 1999 [EMAIL PROTECTED] wrote: Hello -- there is a lot of confusing and incorrect howto's, etc. out there. I was using raid0 with kernel 2.2.5 just fine. I have upgraded the kernel to 2.2.12 in an effort to solve a SMP kernel gen problem, and I can not get raid0 to work at all.. Any advice, including rtm is fine if given the real manual or doc. see http://ostenfeld.dk/~jakob/Software-RAID.HOWTO/ good luck! *---(*)---**-- Francisco J. Montilla System Network administrator [EMAIL PROTECTED] irc: pukkaSevilleSpain INSFLUG (LiNUX) Coordinator: www.insflug.org - ftp.insflug.org
Re: Hardware Raid Questions/Suggestions?
On Mon, 26 Jul 1999, James Deptuck wrote: Does anyone have any experiences with particular hardware raid controlers that they'd be willing to share? What's the most reliable controler? I have experience with the DPT 3334 in several production servers. It may not be the fastest hardware RAID controller (at least it doesn't benchmark as well as some others), but it is very reliable. The real downside is the inability to administer it from Linux - you have to boot DOS to run their administrative software (to create the ranks, manage them after disk failure, etc). I have suffered disk and cabling failures, and the DPT has always kept me going right through them. We would like to put the root partition on raid (everything raided). What problems arise from that? Will linux support that easily with this card? One of the biggest advantages of hardware RAID is that Linux (LILO, or whatever) doesn't *know* it's RAID. The RAID controller BIOS makes it look like any other bootable SCSI disk, so you just boot from it... no black magic needed. -Andy
