[Gluster-users] Self healing

Vikas Gorur vikas at gluster.com
Thu Jul 9 15:29:07 UTC 2009

----- "Hiren Joshi" <josh at moonfruit.com> wrote:

> Hi all,
> I have a setup with 2 nodes mirrored, if I simulate a disk crash (take
> a
> server node out, clear the data and restart it) on the first stat of
> files on the client, it appears to be self healing but during this
> time
> (it's syncing about 2G) the mount point becomes unusable..... is this
> expected behaviour?

Self heal happens whenever a directory or a file is accessed for the first time.
While a file is being self-healed, all other operations on it will be blocked.

So if a 2GB file is being healed, then accesses on that file will be blocked
until self-heal completes. You might see that "ls" done on the mountpoint
is blocked until self heal of _all_ files in the directory completes. This is
because in most cases ls will be aliased to 'ls --color', which causes ls
to do a 'stat' on each file in the directory, thus triggering their self-heal.

Self-healing in the background is in the roadmap.

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