After a reboot recently, my 5-disk RAID6 array wouldn't come up: [root@fileserver log]# mdadm --stop /dev/md0 mdadm: stopped /dev/md0 [root@fileserver log]# mdadm -Af /dev/md0 /dev/sd[bcdef]1 mdadm: /dev/md0 assembled from 2 drives and 3 spares - not enough to start the \ array. I never configured spare drives. I'm trying to determine why md/mdadm has decided that three of my drives should be spare. There is nothing in the logs that indicates a problem with the drives. smartctl reports that all the drives are healthy. I suspected the eSATA cable so I swapped it for a new one. I suspected the enclosure's backplane so I swapped it for a new one of the same model. What else can I try? When I powered up the new enclosure, here is what I saw in my /var/log/messages. It looks normal to me. Are there any hints here? Jun 12 05:31:52 fileserver kernel: ata3.00: ATA-8: WDC WD20EADS-00R6B0, 01.00A01, max UDMA/133 Jun 12 05:31:52 fileserver kernel: ata3.00: 3907029168 sectors, multi 0: LBA48 NCQ (depth 31/32) Jun 12 05:31:52 fileserver kernel: ata3.00: configured for UDMA/100 Jun 12 05:31:53 fileserver kernel: ata3.01: ATA-8: WDC WD20EADS-00R6B0, 01.00A01, max UDMA/133 Jun 12 05:31:53 fileserver kernel: ata3.01: 3907029168 sectors, multi 0: LBA48 NCQ (depth 31/32) Jun 12 05:31:53 fileserver kernel: ata3.01: configured for UDMA/100 Jun 12 05:31:53 fileserver kernel: ata3.02: ATA-8: WDC WD20EADS-00R6B0, 01.00A01, max UDMA/133 Jun 12 05:31:53 fileserver kernel: ata3.02: 3907029168 sectors, multi 0: LBA48 NCQ (depth 31/32) Jun 12 05:31:53 fileserver kernel: ata3.02: configured for UDMA/100 Jun 12 05:31:53 fileserver kernel: ata3.03: ATA-8: WDC WD20EADS-00R6B0, 01.00A01, max UDMA/133 Jun 12 05:31:53 fileserver kernel: ata3.03: 3907029168 sectors, multi 0: LBA48 NCQ (depth 31/32) Jun 12 05:31:53 fileserver kernel: ata3.03: configured for UDMA/100 Jun 12 05:31:53 fileserver kernel: ata3.04: ATA-8: WDC WD20EADS-00R6B0, 01.00A01, max UDMA/133 Jun 12 05:31:53 fileserver kernel: ata3.04: 3907029168 sectors, multi 0: LBA48 NCQ (depth 31/32) Jun 12 05:31:53 fileserver kernel: ata3.04: configured for UDMA/100 Jun 12 05:31:53 fileserver kernel: ata3: EH complete Jun 12 05:31:53 fileserver kernel: scsi 2:0:0:0: Direct-Access ATA WDC WD20EADS-00R 01.0 PQ: 0 ANSI: 5 Jun 12 05:31:53 fileserver kernel: sd 2:0:0:0: [sdb] 3907029168 512-byte hardware sectors (2000399 MB) Jun 12 05:31:53 fileserver kernel: sd 2:0:0:0: [sdb] Write Protect is off Jun 12 05:31:53 fileserver kernel: sd 2:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA Jun 12 05:31:53 fileserver kernel: sd 2:0:0:0: [sdb] 3907029168 512-byte hardware sectors (2000399 MB) Jun 12 05:31:53 fileserver kernel: sd 2:0:0:0: [sdb] Write Protect is off Jun 12 05:31:53 fileserver kernel: sd 2:0:0:0: [sdb] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA Jun 12 05:31:53 fileserver kernel: sdb: sdb1 Jun 12 05:31:53 fileserver kernel: sd 2:0:0:0: [sdb] Attached SCSI disk Jun 12 05:31:53 fileserver kernel: sd 2:0:0:0: Attached scsi generic sg1 type 0 Jun 12 05:31:53 fileserver kernel: scsi 2:1:0:0: Direct-Access ATA WDC WD20EADS-00R 01.0 PQ: 0 ANSI: 5 Jun 12 05:31:53 fileserver kernel: sd 2:1:0:0: [sdc] 3907029168 512-byte hardware sectors (2000399 MB) Jun 12 05:31:53 fileserver kernel: sd 2:1:0:0: [sdc] Write Protect is off Jun 12 05:31:53 fileserver kernel: sd 2:1:0:0: [sdc] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA Jun 12 05:31:53 fileserver kernel: sd 2:1:0:0: [sdc] 3907029168 512-byte hardware sectors (2000399 MB) Jun 12 05:31:53 fileserver kernel: sd 2:1:0:0: [sdc] Write Protect is off Jun 12 05:31:53 fileserver kernel: sd 2:1:0:0: [sdc] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA Jun 12 05:31:53 fileserver kernel: sdc: sdc1 Jun 12 05:31:53 fileserver kernel: sd 2:1:0:0: [sdc] Attached SCSI disk Jun 12 05:31:53 fileserver kernel: sd 2:1:0:0: Attached scsi generic sg2 type 0 Jun 12 05:31:53 fileserver kernel: scsi 2:2:0:0: Direct-Access ATA WDC WD20EADS-00R 01.0 PQ: 0 ANSI: 5 Jun 12 05:31:53 fileserver kernel: sd 2:2:0:0: [sdd] 3907029168 512-byte hardware sectors (2000399 MB) Jun 12 05:31:53 fileserver kernel: sd 2:2:0:0: [sdd] Write Protect is off Jun 12 05:31:53 fileserver kernel: sd 2:2:0:0: [sdd] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA Jun 12 05:31:53 fileserver kernel: sd 2:2:0:0: [sdd] 3907029168 512-byte hardware sectors (2000399 MB) Jun 12 05:31:53 fileserver kernel: sd 2:2:0:0: [sdd] Write Protect is off Jun 12 05:31:53 fileserver kernel: sd 2:2:0:0: [sdd] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA Jun 12 05:31:53 fileserver kernel: sdd: sdd1 Jun 12 05:31:53 fileserver kernel: sd 2:2:0:0: [sdd] Attached SCSI disk Jun 12 05:31:53 fileserver kernel: sd 2:2:0:0: Attached scsi generic sg3 type 0 Jun 12 05:31:53 fileserver kernel: scsi 2:3:0:0: Direct-Access ATA WDC WD20EADS-00R 01.0 PQ: 0 ANSI: 5 Jun 12 05:31:53 fileserver kernel: sd 2:3:0:0: [sde] 3907029168 512-byte hardware sectors (2000399 MB) Jun 12 05:31:53 fileserver kernel: sd 2:3:0:0: [sde] Write Protect is off Jun 12 05:31:53 fileserver kernel: sd 2:3:0:0: [sde] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA Jun 12 05:31:53 fileserver kernel: sd 2:3:0:0: [sde] 3907029168 512-byte hardware sectors (2000399 MB) Jun 12 05:31:53 fileserver kernel: sd 2:3:0:0: [sde] Write Protect is off Jun 12 05:31:53 fileserver kernel: sd 2:3:0:0: [sde] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA Jun 12 05:31:53 fileserver kernel: sde: sde1 Jun 12 05:31:53 fileserver kernel: sd 2:3:0:0: [sde] Attached SCSI disk Jun 12 05:31:53 fileserver kernel: sd 2:3:0:0: Attached scsi generic sg4 type 0 Jun 12 05:31:53 fileserver kernel: scsi 2:4:0:0: Direct-Access ATA WDC WD20EADS-00R 01.0 PQ: 0 ANSI: 5 Jun 12 05:31:53 fileserver kernel: sd 2:4:0:0: [sdf] 3907029168 512-byte hardware sectors (2000399 MB) Jun 12 05:31:53 fileserver kernel: sd 2:4:0:0: [sdf] Write Protect is off Jun 12 05:31:53 fileserver kernel: sd 2:4:0:0: [sdf] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA Jun 12 05:31:53 fileserver kernel: sd 2:4:0:0: [sdf] 3907029168 512-byte hardware sectors (2000399 MB) Jun 12 05:31:53 fileserver kernel: sd 2:4:0:0: [sdf] Write Protect is off Jun 12 05:31:53 fileserver kernel: sd 2:4:0:0: [sdf] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA Jun 12 05:31:53 fileserver kernel: sdf: sdf1 Jun 12 05:31:53 fileserver kernel: sd 2:4:0:0: [sdf] Attached SCSI disk Jun 12 05:31:53 fileserver kernel: sd 2:4:0:0: Attached scsi generic sg5 type 0 Jun 12 05:32:42 fileserver kernel: md: md0 stopped. Jun 12 05:32:56 fileserver kernel: md: md0 stopped. Jun 12 05:32:58 fileserver kernel: md: bind<sde1> Jun 12 05:32:58 fileserver kernel: md: bind<sdf1> Jun 12 05:32:58 fileserver kernel: md: bind<sdc1> Jun 12 05:32:58 fileserver kernel: md: bind<sdb1> Jun 12 05:32:58 fileserver kernel: md: bind<sdd1> Thanks for any advice you might have. Dave -- 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
