software raid- Swap lost

[Markus Schönhaber]

Franz Waldmüller:

> I just noticed my ubuntu 8.04 (all updates) is not using the swap space 
> any more. I have configured a software raid 1 (with the alternate CD 
> back in june last year), All 7 partitions use a seperate md device.
> /boot, /, Swap, /tmp, /var, /home, /data
> 
> cat /proc/mdstat shows that md2, the Raid device of the swap space is 
> "inactive".
> md2 : inactive sda3[0](S) sdb3[1](S)
>        6441856 blocks

I'm not too familiar with the contents of /proc/mdadm, but my guess
would be that "(S)" means the corresponding physical device is seen as
spare.
mdadm --detail /dev/md2
should print something more legible, that either confirms my guess or
disproves it.

> I tried to switch on swap with this command (I am not quite sure about 
> the command - just tried it out)
> 
> sudo swapon -L /dev/md2

No, with -L you'd have to provide the device's label not it' node.
Anyway, since /dev/md2 is inactive you won't have much luck in
swapon'ing it.

The first thing I'd try would be
mdadm --assemble --scan
Maybe this re-activates the RAID device. If not, the above mentioned
output of
mdadm --detail /dev/md2
might prove helpful.

-- 
Regards
  mks