Wow, talk about bad timing. Just had an alert raised from our systems to say that /dev/sda has just failed - I guess /dev/sdd was 100% dead, and /dev/sda was just playing hide and seek :) Really sorry for raising this, I genuinely thought there was a problem with the kernel in some sorts. Thanks for your quick response though! Cal On Thu, Jan 5, 2012 at 2:18 AM, Cal Leeming [Simplicity Media Ltd] <cal.leeming@xxxxxxxxxxxxxxxxxxxxxxxx> wrote: > Hi Neil, > > Terribly sorry, I had pasted the wrong lines from mdstat, here is the > correct info: > > md1 : active (auto-read-only) raid1 sdd1[0] sda1[1] > 975860 blocks super 1.2 [2/2] [UU] > > Also, I don't know if this is related and will probably sound crazy > but, every single disk in the server (there was another unrelated > RAID1 with non SDDs - sdb and sdc) were reporting this same error, but > the moment I disabled the broken SSD in BIOS, it stopped doing this. > > root@vicky [/sbin] > dmesg | grep sda | grep "I/O error" | wc -l > 445 > > root@vicky [/sbin] > dmesg | grep sdb | grep "I/O error" | wc -l > 2 > > root@vicky [/sbin] > dmesg | grep sdc | grep "I/O error" | wc -l > 2 > > root@vicky [/sbin] > dmesg | grep sdd | grep "I/O error" | wc -l > 2 > > root@vicky [/sbin] > > > And here's the really crazy thing.. the broken SSD was actually > /dev/sdd, not /dev/sda. > > I did a badblocks check on both, sdd failed and sda worked fine. > Removed sdd, and the I/O error problem disappeared on both sdd and > sda. > > Could this be the reason why it ended up being placed into read-only > mode? Because the kernel detected that the controller was saying that > both SSDs were giving this same "I/O Error" (despite it being caused > by a single drive)?? > > Cal > > > On Thu, Jan 5, 2012 at 2:00 AM, NeilBrown <neilb@xxxxxxx> wrote: >> On Thu, 5 Jan 2012 01:44:10 +0000 "Cal Leeming [Simplicity Media Ltd]" >> <cal.leeming@xxxxxxxxxxxxxxxxxxxxxxxx> wrote: >> >>> Hi all, >>> >>> My apologies if this is the wrong mailing list for this issue, but I >>> figured my email would be lost in volume if I sent to 'linux-kernel'. >> >> too true!! >> >>> >>> In short, I had 2 SSDs in RAID 1, allocated as a single physical >>> volume, which had a LVM logical volume mounted as the root partition. >>> >>> Six months later, one of the SSDs dies, and causes all of hell to break lose: >>> >>> [27087.234675] sd 0:0:0:0: [sda] Unhandled error code >>> [27087.234686] sd 0:0:0:0: [sda] Result: hostbyte=DID_BAD_TARGET >>> driverbyte=DRIVER_OK >>> [27087.234688] sd 0:0:0:0: [sda] CDB: Read(10): 28 00 00 68 53 88 00 00 08 00 >>> [27087.234693] end_request: I/O error, dev sda, sector 6837128 >> ^^^^^^^^ >> >> "sda". >> >>> ^^ repeated over 9000 times >>> >>> Instead of the disk being marked as failed and removed, the root >>> partition was instead remounted as read-only, mdadm showed no >>> problems, and required a reboot. >>> >>> Upon rebooting, RAID still hadn't marked the dying disk as failed or >>> removed, and began to re-sync! >>> >>> root@vicky [/var/log] > cat /proc/mdstat >>> Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] >>> md0 : active (auto-read-only) raid1 sdb1[0] sdc1[1] >> ^^^^^^^^^^^^^^^ >> >> "sdb" and "sdc". >> >> Something is missing in this picture. >> >> NeilBrown >> >> >>> 78122967 blocks super 1.2 [2/2] [UU] >>> >>> On top of this, even though it was read-only, it kept giving this >>> error for everything: >>> >>> root@vicky [/var/log] > shutdown >>> bash: /sbin/shutdown: Input/output error >>> >>> I'm not sure if what I'm seeing here is normal, but thought I should >>> at least try and ask - I can provide lots more info if needed (got a >>> huge text file and several screenshots). >>> >>> Any feedback would be very much appreciated. >>> >>> Cal Leeming >>> Simplicity Media Ltd >>> >>> ---------------------------- >>> >>> Here is the short smartctl dump of the disk: >>> >>> root@vicky [/home/foxx] > smartctl -a /dev/sda >>> smartctl 5.40 2010-07-12 r3124 [x86_64-unknown-linux-gnu] (local build) >>> Copyright (C) 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net >>> >>> === START OF INFORMATION SECTION === >>> Device Model: M4-CT128M4SSD2 >>> Serial Number: 00000000111603061D7B >>> Firmware Version: 0001 >>> User Capacity: 128,035,676,160 bytes >>> Device is: Not in smartctl database [for details use: -P showall] >>> ATA Version is: 8 >>> ATA Standard is: ATA-8-ACS revision 6 >>> Local Time is: Tue Jan 3 13:54:46 2012 GMT >>> SMART support is: Available - device has SMART capability. >>> SMART support is: Enabled >>> -- >>> 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 >> -- 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
