I have 4x2TB disks configured for RAID5.
Initially they were in a USB3 external caddy but this never worked correctly - the raid kept dropping offline before it completed building the array.
I then switched to eSATA (same caddy) and that improved things but I still failed to build the array completely. So they're now in a new HP microserver.
Until now I assumed the issues were connectivity but since I still have the same problem there must be a disk issue of some kind. However SMART is reporting healthy even after longer self tests.
Do I just right this off as a duff disk or can I investigate this further?
syslog reports thus: Oct 4 01:30:09 backup kernel: [49309.671201] sd 4:0:0:0: [sdd] Unhandled error code Oct 4 01:30:09 backup kernel: [49309.671217] sd 4:0:0:0: [sdd] Oct 4 01:30:09 backup kernel: [49309.671222] Result: hostbyte=DID_OK driverbyte=DRIVER_TIMEOUT Oct 4 01:30:09 backup kernel: [49309.671229] sd 4:0:0:0: [sdd] CDB: Oct 4 01:30:09 backup kernel: [49309.671233] Read(10): 28 00 d9 2e b1 f0 00 04 00 00 Oct 4 01:30:09 backup kernel: [49309.671253] end_request: I/O error, dev sdd, sector 3643716080 Oct 4 01:30:09 backup kernel: [49309.671264] md/raid:md0: read error not correctable (sector 3643714032 on sdd1). Oct 4 01:30:09 backup kernel: [49309.671274] md/raid:md0: Disk failure on sdd1, disabling device. Oct 4 01:30:09 backup kernel: [49309.671274] md/raid:md0: Operation continuing on 2 devices. Oct 4 01:30:09 backup kernel: [49309.671310] md/raid:md0: read error not correctable (sector 3643714040 on sdd1). Oct 4 01:30:09 backup kernel: [49309.671316] md/raid:md0: read error not correctable (sector 3643714048 on sdd1). Oct 4 01:30:09 backup kernel: [49309.671321] md/raid:md0: read error not correctable (sector 3643714056 on sdd1). Oct 4 01:30:09 backup kernel: [49309.671326] md/raid:md0: read error not correctable (sector 3643714064 on sdd1). Oct 4 01:30:09 backup kernel: [49309.671331] md/raid:md0: read error not correctable (sector 3643714072 on sdd1). Oct 4 01:30:09 backup kernel: [49309.671336] md/raid:md0: read error not correctable (sector 3643714080 on sdd1). Oct 4 01:30:09 backup kernel: [49309.671341] md/raid:md0: read error not correctable (sector 3643714088 on sdd1). Oct 4 01:30:09 backup kernel: [49309.671346] md/raid:md0: read error not correctable (sector 3643714096 on sdd1). Oct 4 01:30:09 backup kernel: [49309.671351] md/raid:md0: read error not correctable (sector 3643714104 on sdd1). Oct 4 01:30:09 backup kernel: [49310.107789] md: md0: recovery done. Oct 4 01:30:09 backup kernel: [49310.170142] RAID conf printout: Oct 4 01:30:09 backup kernel: [49310.170156] --- level:5 rd:4 wd:2 Oct 4 01:30:09 backup kernel: [49310.170163] disk 0, o:1, dev:sdb1 Oct 4 01:30:09 backup kernel: [49310.170167] disk 1, o:1, dev:sdc1 Oct 4 01:30:09 backup kernel: [49310.170171] disk 2, o:0, dev:sdd1 Oct 4 01:30:09 backup kernel: [49310.170175] disk 3, o:1, dev:sde1 Oct 4 01:30:09 backup kernel: [49310.170279] RAID conf printout: Oct 4 01:30:09 backup kernel: [49310.170292] --- level:5 rd:4 wd:2 Oct 4 01:30:09 backup kernel: [49310.170299] disk 0, o:1, dev:sdb1 Oct 4 01:30:09 backup kernel: [49310.170304] disk 1, o:1, dev:sdc1 Oct 4 01:30:09 backup kernel: [49310.170309] disk 2, o:0, dev:sdd1 Oct 4 01:30:09 backup kernel: [49310.170322] RAID conf printout: Oct 4 01:30:09 backup kernel: [49310.170325] --- level:5 rd:4 wd:2 Oct 4 01:30:09 backup kernel: [49310.170329] disk 0, o:1, dev:sdb1 Oct 4 01:30:09 backup kernel: [49310.170332] disk 1, o:1, dev:sdc1 Oct 4 01:30:09 backup kernel: [49310.170336] disk 2, o:0, dev:sdd1 Oct 4 01:30:09 backup sSMTP[10706]: Unable to locate mail Oct 4 01:30:09 backup sSMTP[10706]: Cannot open mail:25 Oct 4 01:30:09 backup mdadm[3415]: Fail event detected on md device /dev/md0, component device /dev/sdd1 Oct 4 01:30:09 backup kernel: [49310.172571] RAID conf printout: Oct 4 01:30:09 backup kernel: [49310.172578] --- level:5 rd:4 wd:2 Oct 4 01:30:09 backup kernel: [49310.172585] disk 0, o:1, dev:sdb1 Oct 4 01:30:09 backup kernel: [49310.172589] disk 1, o:1, dev:sdc1 Oct 4 01:30:09 backup mdadm[3415]: RebuildFinished event detected on md device /dev/md0
Mark