As an additional data point, here's a libata problem I'm having trying to rebuild the array. I have six identical 400 GB drives (ST3400832AS), and one is giving me hassles. I've run SMART short and long diagnostics, badblocks, and Seagate's "seatools" diagnostic software, and none of these find problems. It is the only one of the six with a non-zero reallocated sector count (it's 26). Anyway, the drive is partitioned into a 45G RAID-10 part and a 350G RAID-5 part. The RAID-10 part integrated successfully, but the RAID-5 got to about 60% and then puked: ata5.00: exception Emask 0x0 SAct 0x1ef SErr 0x0 action 0x2 frozen ata5.00: cmd 61/c0:00:d2:d0:b9/00:00:1c:00:00/40 tag 0 cdb 0x0 data 98304 out res 40/00:01:01:4f:c2/00:00:00:00:00/00 Emask 0x4 (timeout) ata5.00: cmd 61/40:08:92:d1:b9/00:00:1c:00:00/40 tag 1 cdb 0x0 data 32768 out res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout) ata5.00: cmd 61/00:10:d2:d1:b9/01:00:1c:00:00/40 tag 2 cdb 0x0 data 131072 out res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout) ata5.00: cmd 61/00:18:d2:d2:b9/01:00:1c:00:00/40 tag 3 cdb 0x0 data 131072 out res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout) ata5.00: cmd 61/00:28:d2:d3:b9/01:00:1c:00:00/40 tag 5 cdb 0x0 data 131072 out res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout) ata5.00: cmd 61/00:30:d2:d4:b9/01:00:1c:00:00/40 tag 6 cdb 0x0 data 131072 out res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout) ata5.00: cmd 61/00:38:d2:d5:b9/01:00:1c:00:00/40 tag 7 cdb 0x0 data 131072 out res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout) ata5.00: cmd 61/00:40:d2:d6:b9/01:00:1c:00:00/40 tag 8 cdb 0x0 data 131072 out res 40/00:00:00:00:00/00:00:00:00:00/00 Emask 0x4 (timeout) ata5: soft resetting port ata5: SATA link up 1.5 Gbps (SStatus 113 SControl 300) ata5.00: configured for UDMA/100 ata5: EH complete SCSI device sde: 781422768 512-byte hdwr sectors (400088 MB) sde: Write Protect is off SCSI device sde: write cache: enabled, read cache: enabled, doesn't support DPO or FUA ata5.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x2 frozen ata5.00: cmd ea/00:00:00:00:00/00:00:00:00:00/a0 tag 0 cdb 0x0 data 0 res 40/00:01:01:4f:c2/00:00:00:00:00/00 Emask 0x4 (timeout) ata5: soft resetting port ata5: softreset failed (timeout) ata5: softreset failed, retrying in 5 secs ata5: hard resetting port ata5: softreset failed (timeout) ata5: follow-up softreset failed, retrying in 5 secs ata5: hard resetting port ata5: softreset failed (timeout) ata5: reset failed, giving up ata5.00: disabled ata5: EH complete sd 4:0:0:0: SCSI error: return code = 0x00040000 end_request: I/O error, dev sde, sector 91795259 md: super_written gets error=-5, uptodate=0 raid10: Disk failure on sde3, disabling device. Operation continuing on 5 devices sd 4:0:0:0: SCSI error: return code = 0x00040000 end_request: I/O error, dev sde, sector 481942994 raid5: Disk failure on sde4, disabling device. Operation continuing on 5 devices sd 4:0:0:0: SCSI error: return code = 0x00040000 end_request: I/O error, dev sde, sector 481944018 md: md5: recovery done. RAID10 conf printout: --- wd:5 rd:6 disk 0, wo:0, o:1, dev:sdb3 disk 1, wo:0, o:1, dev:sdc3 disk 2, wo:0, o:1, dev:sdd3 disk 3, wo:1, o:0, dev:sde3 disk 4, wo:0, o:1, dev:sdf3 disk 5, wo:0, o:1, dev:sda3 RAID10 conf printout: --- wd:5 rd:6 disk 0, wo:0, o:1, dev:sdb3 disk 1, wo:0, o:1, dev:sdc3 disk 2, wo:0, o:1, dev:sdd3 disk 4, wo:0, o:1, dev:sdf3 disk 5, wo:0, o:1, dev:sda3 RAID5 conf printout: --- rd:6 wd:5 disk 0, o:1, dev:sda4 disk 1, o:1, dev:sdb4 disk 2, o:1, dev:sdc4 disk 3, o:1, dev:sdd4 disk 4, o:0, dev:sde4 disk 5, o:1, dev:sdf4 RAID5 conf printout: --- rd:6 wd:5 disk 0, o:1, dev:sda4 disk 1, o:1, dev:sdb4 disk 2, o:1, dev:sdc4 disk 3, o:1, dev:sdd4 disk 5, o:1, dev:sdf4 The first error address is just barely inside the RAID-10 part (which ends at sector 91,795,410), while the second and third errors (at 481,942,994) look like where the reconstruction was working. Anyway, what's annoying is that I can't figure out how to bring the drive back on line without resetting the box. It's in a hot-swap enclosure, but power cycling the drive doesn't seem to help. I thought libata hotplug was working? (SiI3132 card, using the sil24 driver.) (H'm... after rebooting, reallocated sectors jumped from 26 to 39. Something is up with that drive.) - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html