Martin Seebach wrote: > Hi, > > I'm not sure this is completely linux-raid related, but I can't figure out where to start: > > A few days ago, my server died. I was able to log in and salvage this content of dmesg: > http://pastebin.com/m4af616df > > I talked to my hosting-people and they said it was an io-error on /dev/sda, and replaced that drive. > After this, I was able to boot into a PXE-image and re-build the two RAID-1 devices with no problems - indicating that sdb was fine. > > I expected RAID-1 to be able to stomach exactly this kind of error - one drive dying. What did I do wrong? from that pastebin page. First, sdb has failed for whatever reason: ata2.00: qc timeout (cmd 0xec) ata2.00: failed to IDENTIFY (I/O error, err_mask=0x4) ata2.00: revalidation failed (errno=-5) ata2.00: disabled ata2: EH complete sd 1:0:0:0: SCSI error: return code = 0x00040000 end_request: I/O error, dev sdb, sector 80324865 raid1: Disk failure on sdb1, disabling device. Operation continuing on 1 devices RAID1 conf printout: --- wd:1 rd:2 disk 0, wo:0, o:1, dev:sda1 disk 1, wo:1, o:0, dev:sdb1 RAID1 conf printout: --- wd:1 rd:2 disk 0, wo:0, o:1, dev:sda1 At this time, it started to (re)sync other(?) arrays for some reason: md: syncing RAID array md0 md: minimum _guaranteed_ reconstruction speed: 1000 KB/sec/disc. md: using maximum available idle IO bandwidth (but not more than 200000 KB/sec) for reconstruction. md: using 128k window, over a total of 40162432 blocks. md: md0: sync done. RAID1 conf printout: --- wd:1 rd:2 disk 0, wo:0, o:1, dev:sda1 md: syncing RAID array md1 md: minimum _guaranteed_ reconstruction speed: 1000 KB/sec/disc. md: using maximum available idle IO bandwidth (but not more than 200000 KB/sec) for reconstruction. md: using 128k window, over a total of 100060736 blocks. Note again, errors on sdb: sd 1:0:0:0: SCSI error: return code = 0x00040000 end_request: I/O error, dev sdb, sector 112455000 sd 1:0:0:0: SCSI error: return code = 0x00040000 end_request: I/O error, dev sdb, sector 112455256 sd 1:0:0:0: SCSI error: return code = 0x00040000 end_request: I/O error, dev sdb, sector 112455512 ... raid1: Disk failure on sdb3, disabling device. Operation continuing on 1 devices so another md array detected sdb failure. So we're with sda only. And volia, sda fails too, some time later: ata1: EH complete sd 0:0:0:0: SCSI error: return code = 0x00040000 end_request: I/O error, dev sda, sector 80324865 sd 0:0:0:0: SCSI error: return code = 0x00040000 end_request: I/O error, dev sda, sector 115481 ... At this point, the arrays are hosed - all disks of each array has failed, there's no data any more to read/write from/to. Since later sda has been replaced, and sdb recovered from the errors (it contains still-valid superblocks but with somewhat stale information), everything went ok. But the original problem is that you had BOTH disks failed, not only one. What caused THIS problem is another question. Maybe some overheating or power unit problem or somesuch, -- I don't know... But md code worked the best it can here. /mjt - 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
