[NTLUG:Discuss] HOW?? - Remirroring SOLVED -or- The mysterious gremlins fix the computer

[Richard Geoffrion]

Richard Geoffrion wrote:
> OK..so there should be nothing TO it.  I should just have to reboot
> the box and the raid mirror should just autorecover...only it's not.
> AND since this is on the [/] root partition I can't just stopraid,
> raidhotadd, or any other raid command on the silly thing because its
> always active.

Well it seems that after the reboot I *CAN* run my raidhotadd command.  So I
did.  FYI, here is the <snip> of the dmesg
[dmesg]
md: considering sdb5 ...
md:  adding sdb5 ...
md:  adding sda5 ...
md: created md1
md: bind<sda5,1>
md: bind<sdb5,2>
md: running: <sdb5><sda5>
md: sdb5's event counter: 00000067
md: sda5's event counter: 00000065
md: superblock update time inconsistency -- using the most recent one
md: freshest: sdb5
md: kicking non-fresh sda5 from array!
md: unbind<sda5,1>
md: export_rdev(sda5)
md1: removing former faulty sda5!
md: md1: raid array is not clean -- starting background reconstruction
md: RAID level 1 does not need chunksize! Continuing anyway.
md1: max total readahead window set to 124k
md1: 1 data-disks, max readahead per data-disk: 124k
raid1: device sdb5 operational as mirror 1
raid1: md1, not all disks are operational -- trying to recover array
raid1: raid set md1 active with 1 out of 2 mirrors
md: updating md1 RAID superblock on device
md: sdb5 [events: 00000068]<6>(write) sdb5's sb offset: 4000064
md: recovery thread got woken up ...
md1: no spare disk to reconstruct array! -- continuing in degraded mode
md: recovery thread finished ...
[/dmesg]


And now to recover the raid array...

root at gwifs:~# raidhotadd /dev/md1 /dev/sda5
root at gwifs:~# cat /proc/mdstat
Personalities : [raid0] [raid1]
read_ahead 1024 sectors
md0 : active raid1 sdb1[1] sda1[0]
      32000 blocks [2/2] [UU]

md1 : active raid1 sda5[2] sdb5[1]
      4000064 blocks [2/1] [_U]
      [===>.................]  recovery = 18.3% (733956/4000064)
finish=1.2min speed=43173K/sec
<snip>