Hi Andre, > Run > mdadm --zero-superblock /dev/dm-0 > > before creating the array to get rid of these. ok, thanks. > > > monosan:~ # mdadm --detail --scan| fgrep md4 >> /etc/mdadm.conf > > Please post your /etc/mdadm.conf monosan:~ # cat /etc/mdadm.conf DEVICE partitions ARRAY /dev/md2 level=raid1 UUID=d9d31de2:e6dbd3c3:37c7ea09:882a64e5 ARRAY /dev/md3 level=raid1 UUID=a8687183:a79e514c:ca492c4b:ffd4384f ARRAY /dev/md4 level=raid6 num-devices=16 UUID=8d596319:4d21dba3:3871bccf:5b90a66d > > monosan:~ # mdadm -A /dev/md4 > > mdadm: WARNING /dev/dm-9 and /dev/dm-8 appear to have very similar superblocks. > > If they are really different, please --zero the superblock on one > > If they are the same or overlap, please remove one from the > > DEVICE list in mdadm.conf. > > Are you sure dm-8 and dm-9 are different devices? > > pvdisplay /dev/dm-9; pvdisplay /dev/dm-8 > > should tell you. Yes, I'm sure: monosan:~ # pvdisplay /dev/dm-9; pvdisplay /dev/dm-8 Failed to read physical volume "/dev/dm-9" Failed to read physical volume "/dev/dm-8" but: monosan:~ # multipathd -k multipathd> list topology mpath0 (SATA_ST31000340NS_5QJ02QRQ) dm-0 ATA ,ST31000340NS [size=932G][features=0][hwhandler=0] \_ round-robin 0 [prio=0][active] \_ 6:0:32:0 sdah 66:16 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 6:0:15:0 sdr 65:16 [active][ready] mpath1 (SATA_ST31000340NS_5QJ0204G) dm-1 ATA ,ST31000340NS [size=932G][features=0][hwhandler=0] \_ round-robin 0 [prio=0][active] \_ 6:0:31:0 sdag 66:0 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 6:0:14:0 sdq 65:0 [active][ready] mpath2 (SATA_ST31000340NS_5QJ02TVQ) dm-2 ATA ,ST31000340NS [size=932G][features=0][hwhandler=0] \_ round-robin 0 [prio=0][active] \_ 6:0:30:0 sdaf 65:240 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 6:0:13:0 sdp 8:240 [active][ready] mpath3 (SATA_ST31000340NS_5QJ012AL) dm-3 ATA ,ST31000340NS [size=932G][features=0][hwhandler=0] \_ round-robin 0 [prio=0][active] \_ 6:0:29:0 sdae 65:224 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 6:0:12:0 sdo 8:224 [active][ready] mpath4 (SATA_ST31000340NS_5QJ00PHN) dm-4 ATA ,ST31000340NS [size=932G][features=0][hwhandler=0] \_ round-robin 0 [prio=0][active] \_ 6:0:28:0 sdad 65:208 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 6:0:11:0 sdn 8:208 [active][ready] mpath5 (SATA_ST31000340NS_5QJ01BYF) dm-5 ATA ,ST31000340NS [size=932G][features=0][hwhandler=0] \_ round-robin 0 [prio=0][active] \_ 6:0:27:0 sdac 65:192 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 6:0:10:0 sdm 8:192 [active][ready] mpath6 (SATA_ST31000340NS_5QJ026J1) dm-6 ATA ,ST31000340NS [size=932G][features=0][hwhandler=0] \_ round-robin 0 [prio=0][active] \_ 6:0:26:0 sdab 65:176 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 6:0:9:0 sdl 8:176 [active][ready] mpath7 (SATA_ST31000340NS_5QJ01G09) dm-7 ATA ,ST31000340NS [size=932G][features=0][hwhandler=0] \_ round-robin 0 [prio=0][active] \_ 6:0:25:0 sdaa 65:160 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 6:0:8:0 sdk 8:160 [active][ready] rename: mpath9 (SATA_ST31000340NS_5QJ02461) dm-8 ATA ,ST31000340NS [size=932G][features=0][hwhandler=0] \_ round-robin 0 [prio=0][active] \_ 6:0:24:0 sdz 65:144 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 6:0:7:0 sdj 8:144 [active][ready] reload: mpath10 (SATA_ST31000340NS_5QJ013GW) dm-9 ATA ,ST31000340NS [size=932G][features=0][hwhandler=0] \_ round-robin 0 [prio=0][active] \_ 6:0:23:0 sdy 65:128 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 6:0:6:0 sdi 8:128 [active][ready] mpath11 (SATA_ST31000340NS_5QJ01835) dm-10 ATA ,ST31000340NS [size=932G][features=0][hwhandler=0] \_ round-robin 0 [prio=0][active] \_ 6:0:22:0 sdx 65:112 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 6:0:5:0 sdh 8:112 [active][ready] mpath12 (SATA_ST31000340NS_5QJ01C49) dm-11 ATA ,ST31000340NS [size=932G][features=0][hwhandler=0] \_ round-robin 0 [prio=0][active] \_ 6:0:21:0 sdw 65:96 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 6:0:4:0 sdg 8:96 [active][ready] mpath13 (SATA_ST31000340NS_5QJ02TBZ) dm-12 ATA ,ST31000340NS [size=932G][features=0][hwhandler=0] \_ round-robin 0 [prio=0][active] \_ 6:0:20:0 sdv 65:80 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 6:0:3:0 sdf 8:80 [active][ready] mpath14 (SATA_ST31000340NS_5QJ01JSF) dm-13 ATA ,ST31000340NS [size=932G][features=0][hwhandler=0] \_ round-robin 0 [prio=0][active] \_ 6:0:19:0 sdu 65:64 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 6:0:2:0 sde 8:64 [active][ready] mpath15 (SATA_ST31000340NS_5QJ02TBK) dm-14 ATA ,ST31000340NS [size=932G][features=0][hwhandler=0] \_ round-robin 0 [prio=0][active] \_ 6:0:18:0 sdt 65:48 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 6:0:1:0 sdd 8:48 [active][ready] mpath16 (SATA_ST31000340NS_5QJ0185Y) dm-15 ATA ,ST31000340NS [size=932G][features=0][hwhandler=0] \_ round-robin 0 [prio=0][active] \_ 6:0:17:0 sds 65:32 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 6:0:0:0 sdc 8:32 [active][ready] multipathd> monosan:~ # for DEV in /dev/sd[c-z] /dev/sda[a-h] ; do echo Serial $DEV ; smartctl -id sat $DEV ; done | fgrep Serial Serial /dev/sdc Serial Number: 5QJ0185Y Serial /dev/sdd Serial Number: 5QJ02TBK Serial /dev/sde Serial Number: 5QJ01JSF Serial /dev/sdf Serial Number: 5QJ02TBZ Serial /dev/sdg Serial Number: 5QJ01C49 Serial /dev/sdh Serial Number: 5QJ01835 Serial /dev/sdi Serial Number: 5QJ013GW Serial /dev/sdj Serial Number: 5QJ02461 Serial /dev/sdk Serial Number: 5QJ01G09 Serial /dev/sdl Serial Number: 5QJ026J1 Serial /dev/sdm Serial Number: 5QJ01BYF Serial /dev/sdn Serial Number: 5QJ00PHN Serial /dev/sdo Serial Number: 5QJ012AL Serial /dev/sdp Serial Number: 5QJ02TVQ Serial /dev/sdq Serial Number: 5QJ0204G Serial /dev/sdr Serial Number: 5QJ02QRQ Serial /dev/sds Serial Number: 5QJ0185Y Serial /dev/sdt Serial Number: 5QJ02TBK Serial /dev/sdu Serial Number: 5QJ01JSF Serial /dev/sdv Serial Number: 5QJ02TBZ Serial /dev/sdw Serial Number: 5QJ01C49 Serial /dev/sdx Serial Number: 5QJ01835 Serial /dev/sdy Serial Number: 5QJ013GW Serial /dev/sdz Serial Number: 5QJ02461 Serial /dev/sdaa Serial Number: 5QJ01G09 Serial /dev/sdab Serial Number: 5QJ026J1 Serial /dev/sdac Serial Number: 5QJ01BYF Serial /dev/sdad Serial Number: 5QJ00PHN Serial /dev/sdae Serial Number: 5QJ012AL Serial /dev/sdaf Serial Number: 5QJ02TVQ Serial /dev/sdag Serial Number: 5QJ0204G Serial /dev/sdah Serial Number: 5QJ02QRQ > > > This happens _always_ when the arreay is reassembled. The actual > > devices with the duplicated superblocks differ sometimes. > > If I read the code correctly it means that the two devices have > identical superblocks, the same event count and the same minor number, > so mdadm thinks dm-8 and dm-9 are overlapping partitions. The multipathed drives are used as a whole without. The dont contain any partitions. sdz and sdj are the same physical device with serial 5QJ02461 called /dev/dm-8: rename: mpath9 (SATA_ST31000340NS_5QJ02461) dm-8 ATA ,ST31000340NS [size=932G][features=0][hwhandler=0] \_ round-robin 0 [prio=0][active] \_ 6:0:24:0 sdz 65:144 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 6:0:7:0 sdj 8:144 [active][ready] similar to sdy and sdi with serial 5QJ013GW called /dev/dm-9 reload: mpath10 (SATA_ST31000340NS_5QJ013GW) dm-9 ATA ,ST31000340NS [size=932G][features=0][hwhandler=0] \_ round-robin 0 [prio=0][active] \_ 6:0:23:0 sdy 65:128 [active][ready] \_ round-robin 0 [prio=0][enabled] \_ 6:0:6:0 sdi 8:128 [active][ready] > > Are 16 drivesmda too much for RAID6? > > No, raid6 supports up to 254 devices (there are other reasons for > not using too many devices for raid6 though). Is there a way to get more verbose infos or debug this anyhow? Thanks Lars -- 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
