On Thu, Oct 21 2004, Paul Clements wrote: > Jens Axboe wrote: > >On Wed, Oct 20 2004, Mark Rustad wrote: > > > >>Folks, > >> > >>I have been having trouble with kernel crashes resulting from RAID1 > >>component device failures. I have been testing the robustness of an > >>embedded system and have been using a drive that is known to fail after > >>a time under load. When this device returns a media error, I always > >>wind up with either a kernel hang or reboot. In this environment, each > >>drive has four partitions, each of which is part of a RAID1 with its > >>partner on the other device. Swap is on md2 so even it should be > >>robust. > >> > >>I have gotten this result with the SuSE standard i386 smp kernels > >>2.6.5-7.97 and 2.6.5-7.108. I also get these failures with the > >>kernel.org kernels 2.6.8.1, 2.6.9-rc4 and 2.6.9. > >> > >>The hardware setup is a two cpu Nacona with an Adaptec 7902 SCSI > >>controller with two Seagate drives on a SAF-TE bus. I run three or four > >>dd commands copying /dev/md0 to /dev/null to provide the activity that > >>stimulates the failure. > >> > >>I suspect that something is going wrong in the retry of the failed I/O > >>operations, but I'm really not familiar with any of this area of the > >>kernel at all. > >> > >>In one failure, I get the following messages from kernel 2.6.9: > >> > >>raid1: Disk failure on sdb1, disabling device. > >>raid1: sdb1: rescheduling sector 176 > >>raid1: sda1: redirecting sector 176 to another mirror > >>raid1: sdb1: rescheduling sector 184 > >>raid1: sda1: redirecting sector 184 to another mirror > >>Incorrect number of segments after building list > >>counted 2, received 1 > >>req nr_sec 0, cur_nr_sec 7 > > > > > >This should be fixed by this patch, can you test it? > > There may well be two problems here, but the original problem you're > seeing (infinite read retries, and failures) is due to a bug in raid1. > Basically the bio handling on read error retry was not quite right. Neil > Brown just posted the patch to correct this a couple of days ago: > > http://marc.theaimsgroup.com/?l=linux-raid&m=109824318202358&w=2 > > Please try that. (If you need a patch that applies to SUSE 2.6.5, I also > have a version of the patch which should apply to that). Is 2.6.9 not uptodate wrt those raid1 patches?! > Please be aware that there are several other bugs in the SUSE 2.6.5-7.97 > kernel in md and raid1 (basically it's a matter of that kernel being > somewhat behind mainline, where most of these bugs are now fixed). I've > sent several patches to SUSE to fix these issues, that hopefully will > get into their SP1 release that should be forthcoming soon... -97 is the release kernel, -111 is the current update kernel. And it has those raid1 issues fixed already, at least the ones that are known. The scsi segment issue is not, however. -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
