I upgraded my server to beowulf.

After rebooting, all home directories except root's are no longer
accessible.

They are all on an LVM on software RAID.

The problem seems to be that two of my three RAID1 systems are not
starting up properly. What can I do about it?

hendrik@april:/$ cat /proc/mdstat
Personalities : [raid1] [linear] [multipath] [raid0] [raid6] [raid5]
[raid4] [raid10]
md1 : inactive sda2[3](S)
      2391296000 blocks super 1.2

md2 : inactive sda3[0](S)
      1048512 blocks

md0 : active raid1 sdf4[1]
      706337792 blocks [2/1] [_U]

unused devices: <none>
hendrik@april:/$



hendrik@april:/$ cat /etc/mdadm/mdadm.conf
DEVICE partitions
ARRAY /dev/md0 level=raid1 num-devices=2
UUID=4dc189ba:e7a12d38:e6262cdf:db1beda2
ARRAY /dev/md1 metadata=1.2 name=april:1
UUID=c328565c:16dce536:f16da6e2:db603645
ARRAY /dev/md2 UUID=5d63f486:183fd2ea:c2a3a88f:cb2b61de
MAILADDR root
hendrik@april:/$



The standard recommendation seems to be to replace lines
in /etc/mdadm/mdadm.conf by lines prouced by mdadm --examine --scan:



april:~# mdadm --examine --scan
ARRAY /dev/md/1 metadata=1.2 UUID=c328565c:16dce536:f16da6e2:db603645
name=april:1
ARRAY /dev/md2 UUID=5d63f486:183fd2ea:c2a3a88f:cb2b61de
ARRAY /dev/md0 UUID=4dc189ba:e7a12d38:e6262cdf:db1beda2
april:~#



But this replacement involves changing a line that dies work (md0),
not changing one that did not (md2),
and changing another one that did not work (md1).

Since --examine's suggested changes seem uncorrelated
with the active/inactive record, I have little faith in
this alleged fix without first gaining more understanding.

-- hendrik