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

[Nathan Stratton]

On Tue, 4 Aug 2009, Vikas Gorur wrote:

> 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).

The problem was ls was aliased to 'ls --color=auto', need to make sure I 
fix this on all my systems.

>> 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.

Odd, all operations look locked during self-heal.

>> 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.

Is a recent kernel, or recent FUSE module required? I.E. Xen is something 
that right now is stuck in the 2.6.18 world until at least 2.6.33.

You mention "forthcoming FUSE improvements" is this in the new 2.8 fuse or 
gluster? Any time frame?

> 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.

Great!

><>
Nathan Stratton                                CTO, BlinkMind, Inc.
nathan at robotics.net                         nathan at blinkmind.com
http://www.robotics.net                        http://www.blinkmind.com