On Fri, 18 Apr 2008, Christopher Hawkins wrote:
I can see that it's less of an issue than block-level
split-brain, because this would at most lead to the odd file
getting corrupted, whereas block-level split-brain would
destroy the entire FS very quickly.
Good distinction. You are certainly right that there are
more possibilities for split brain than I am thinking of, but wouldn't
the worst case scenario be that two versions of the same file(s) are
getting written, and then when you sync only one of them will remain?
Yes, that's right.
In that case you have no corruption, just lost changes on the file that got
tossed.
The line dividing data loss and data corruption is a hazy one, and both
are certainly something to be avoided at all cost.
I'm not sure that corruption is out of the question, just thinking out loud.
Since it's all file based, the FS, in theory, cannot get corrupted any
more than it can with, say, NFS. GlusterFS, from what I have seen so far
in my extremely limited experience of it (2 days so far) seems to have
much more in common with network file systems than it has with cluster
file systems.
Gordan
