[Sheepdog] Drive Failure

[MORITA Kazutaka]

Hi,

Thanks for your feedbacks.

At Sat, 23 Apr 2011 20:17:33 -0500,
Greg Zapp wrote:
> I have sheepdog running on two nodes.  The sheepdog store is a single drive
> separate from the OS drive.  I'm running an ubuntu VM on node A.  If I force
> unmount the store, the VM craps itself.  Shouldn't sheepdog be able to
> gracefully handle a drive failure or unmounted file system?

Yes, it really should be handled...  In this case, Sheepdog must do
the below automatically:

  - kill the sheep daemon on node A when the store is unavailable
  - failover the VM connection to node B

In particular, the first needs to be resolved as soon as possible
because one disk failure shouldn't affect the availability of total
system.

> 
> Update:
> 
> In order to bring the VM up on node B, I had to kill sheep on node A.
> However, when I remounted the drive and brought sheep back up on node A it
> ruined everything.  I shut down sheep on node A and cleared the store
> directory then brought it back up.  After it synced I was still unable to
> boot the VM on node A or node B.  It's hosed.

This should be handled in the current version and seems to be a bug.
Unfortunately, I couldn't reproduce the problem in my environment.
Your VM couldn't even find the sheepdog volume?  Or your VM found the
volume but hung during boot?


Thanks,

Kazutaka