[Gluster-devel] directory lock durning file self-healing

[Vikas Gorur]

----- "Nathan Stratton" <nathan at robotics.net> wrote:

> Version      : glusterfs 2.0.0git built on Aug  3 2009 16:40:55
> 
> If there is a file self-healing in a directory I am no longer able to
> access any other files in that directory. Is this normal behavior?

You should be able to access other files while a file in a directory
is being self-healed (except for a brief period when directory entries
are being created/deleted).
 
> Also, can you be modifying a file (say a xen file) at the same time it
> is  self-healing? If not, should other files still work with that client
> during a self-heal?

Yes, you can be modifying a file while it is being self-healed.

> Lastly, any way to speed up self-heal with disable-direct-io-mode
> required for xen? It lowers the I/O rate to a crawl from ~500 MB/s to ~25 MB/s.

Two things will help here:

a) With a recent FUSE kernel module (> 2.6.26) and forthcoming FUSE improvements
we'll be able to get good performance even with direct I/O mode disabled.

b) By the 2.1 release, replicate will use the rsync algorithm to do self-heal, which should again
cut down the time required to complete self-heal. 

> Other then that, things are looking so so much better, this is almost
> someting I could put in production!

Virtualization environments are one of our major focus areas right now.
We have contributed to the oVirt project to add GlusterFS support
(http://git.et.redhat.com/?p=ovirt-server.git;a=shortlog;h=refs/heads/next). We
hope you'll use GlusterFS too!

Vikas
-- 
Engineer - http://gluster.com/