On Fri, 2005-05-13 at 11:44 -0400, Doug Ledford wrote: > If you create stacked md devices, ala: > > [root@pe-fc4 devel]# cat /proc/mdstat > Personalities : [raid0] [raid5] [multipath] > md_d0 : active raid5 md3[3] md2[2] md1[1] md0[0] > 53327232 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU] > > md3 : active multipath sdm1[1] sdi1[0] > 17775808 blocks [2/2] [UU] > > md2 : active multipath sdl1[1] sdh1[0] > 17775808 blocks [2/2] [UU] > > md1 : active multipath sdk1[1] sdg1[0] > 17775808 blocks [2/2] [UU] > > md0 : active multipath sdj1[0] sdf1[1] > 17775808 blocks [2/2] [UU] > > unused devices: <none> > [root@pe-fc4 devel]# > > and then run mdadm -E --scan, then you get this (obviously wrong) > output: > > [root@pe-fc4 devel]# /sbin/mdadm -E --scan > ARRAY /dev/md0 level=multipath num-devices=2 > UUID=34f4efec:bafe48ef:f1bb5b94:f5aace52 > devices=/dev/sdj1,/dev/sdf1 > ARRAY /dev/md1 level=multipath num-devices=2 > UUID=bbaaf9fd:a1f118a9:bcaa287b:e7ac8c0f > devices=/dev/sdk1,/dev/sdg1 > ARRAY /dev/md2 level=multipath num-devices=2 > UUID=a719f449:1c63e488:b9344127:98a9bcad > devices=/dev/sdl1,/dev/sdh1 > ARRAY /dev/md3 level=multipath num-devices=2 > UUID=37b23a92:f25ffdc2:153713f7:8e5d5e3b > devices=/dev/sdm1,/dev/sdi1 > ARRAY /dev/md0 level=raid5 num-devices=4 > UUID=910b1fc9:d545bfd6:e4227893:75d72fd8 > > devices=/dev/md3,/dev/md2,/dev/md1,/dev/md0,/dev/md3,/dev/md2,/dev/md1,/dev/md0 > [root@pe-fc4 devel]# > > This is with mdadm-1.11.0. OK, this appears to extend to mdadm -Ss and mdadm -A --scan as well. Basically, mdadm does not properly handle mixed md and mdp type devices well, especially in a stacked configuration. I got it to work reasonably well using this config file: DEVICE partitions /dev/md[0-3] MAILADDR root ARRAY /dev/md0 level=multipath num-devices=2 UUID=34f4efec:bafe48ef:f1bb5b94:f5aace52 auto=md ARRAY /dev/md1 level=multipath num-devices=2 UUID=bbaaf9fd:a1f118a9:bcaa287b:e7ac8c0f auto=md ARRAY /dev/md2 level=multipath num-devices=2 UUID=a719f449:1c63e488:b9344127:98a9bcad auto=md ARRAY /dev/md3 level=multipath num-devices=2 UUID=37b23a92:f25ffdc2:153713f7:8e5d5e3b auto=md ARRAY /dev/md_d0 level=raid5 num-devices=4 UUID=910b1fc9:d545bfd6:e4227893:75d72fd8 auto=part This generates a number of warnings during both assembly and stop, but works. One more thing, since the UUID is a good identifier, it would be nice to have mdadm -E --scan not print a devices= part. Device names can change, and picking up your devices via UUID regardless of that change is preferable, IMO, to having it fail. -- Doug Ledford <dledford@xxxxxxxxxx> http://people.redhat.com/dledford - 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
