[sheepdog-users] About split brain

[Valerio Pachera]

Scenario:

cluster with 3 nodes and a vdi with some snapshots.

Node 0 dies (and sure it didn't flush the cache).

Before Node 0 is back on line, I remove the vdi and its snapshots!

Once Node 0 is back, it's still showing the vdi and the snapshots.

# collie vdi list
  Name        Id    Size    Used  Shared    Creation time   VDI id  Copies  Tag
s big          2   50 GB  0.0 MB   44 MB 2013-08-19 16:12   4fd25e
2
s big          3   50 GB  0.0 MB   44 MB 2013-08-19 16:12   4fd25f
2
s big          4   50 GB  220 MB   40 MB 2013-08-19 16:12   4fd260
2
s big          5   50 GB   40 MB  252 MB 2013-08-19 16:13   4fd261
2
s big          6   50 GB  8.0 MB  284 MB 2013-08-19 16:13   4fd262
2
s big          7   50 GB  460 MB   40 MB 2013-08-19 16:13   4fd263
2
  big          0   50 GB   52 MB  496 MB 2013-08-19 16:13   4fd264     2

If I remove a snapshot from Node 0 I get an error, but it does the job:

# collie  vdi delete -s 1 big
  Failed to delete big: Failed to find requested tag
# collie  vdi delete -s 2 big
  Failed to delete big: Failed to find requested tag

# collie vdi list
  Name        Id    Size    Used  Shared    Creation time   VDI id  Copies  Tag
s big          3   50 GB  0.0 MB   44 MB 2013-08-19 16:12   4fd25f
2
s big          4   50 GB  220 MB   40 MB 2013-08-19 16:12   4fd260
2
s big          5   50 GB   40 MB  252 MB 2013-08-19 16:13   4fd261
2
s big          6   50 GB  8.0 MB  284 MB 2013-08-19 16:13   4fd262
2
s big          7   50 GB  460 MB   40 MB 2013-08-19 16:13   4fd263
2
  big          0   50 GB   52 MB  496 MB 2013-08-19 16:13   4fd264     2

In such situation, I think it's better to clear the node data before
inserting it back on line, as if it was new.

What do you think?

Note: at the and the recovery it's still showing the vdi(s).