[Gluster-users] NFS mounts with glusterd on localhost - reliable or not?

[Tomasz Chmielewski]

On 07/13/2012 05:08 PM, Rajesh Amaravathi wrote:

> The issue was reported earlier, but I don't see any references it was
> fixed in 3.3.0:
>
>
> 	Deadlock happens when writing a file big enough to fill the
> 	filesystem cache and kernel is trying to flush it to free some
> 	memory for glusterfsd which needs memory to commit some
> 	filesystem blocks to free some memory for glusterfsd...
>
>
> http://gluster.org/pipermail/gluster-users/2011-January/006477.html
> https://bugzilla.redhat.com/show_bug.cgi?id=GLUSTER-2320
>
> ****
> This is a problem generic to fuse/userspace filesystems.
> Also, in 3.3, since we have NLM implemented to provide locking for NFS,
> Its not possible to mount from a system which has glusterd(more precisely,
> a Gluster NFS process) running since both kernel nfs and gNFS will try to register
> for NLM v4 with portmapper.

Hmm, this is sad.

gluster/fuse mounts perform very poor for me.

On a 10-server distributed gluster setup, when put to a lot of load, I'm 
able to serve (each server has 1xGbit NIC dedicated for gluster traffic 
and 1xGbit NIC dedicated for external traffic, webservers):

- around 100 Mbit/s with gluster/fuse mounts to glusterd on localhost,

- around 300 Mbit/s with NFS mounts to glusterd on localhost,

- around 500 Mbit/s with NFS mounts to glusterd on localhost, and 
fsc/cachefilesd.


Killing the option to use NFS mounts on localhost is certainly quite the 
opposite to my performance needs!

-- 
Tomasz Chmielewski
http://www.ptraveler.com