samba - Dec 2009 - nfs vs. cifs based on my usage profile

Hello,

I have an interesting architecture consisting of a 3 RHEL 5.3 NFS
nodes that mounts about 30 TB worth of iscsi disk and presents them as
6 different NFS shares.  It is an active-active-active cluster with
each node presenting a couple of shares.  It works pretty well.  I am
doubting my decision to use NFS and am wondering if CIFS would be a
better route.  Here are the NFS stats:

getattr	lookup	access	read	write	readdirplus
20%         16%	        7%	        44%	9%	1%

Each NFS node pushes about 65 MB/s so they are pretty busy.  It is a
backup/recovery application so I would describe the I/O as lots of
small reads/writes.

Any thoughts?

Thanks,
Terry

On Thu, 31 Dec 2009 13:50:10 -0600
Terry <td3201 at gmail.com> wrote:
> Hello,
> 
> I have an interesting architecture consisting of a 3 RHEL 5.3 NFS
> nodes that mounts about 30 TB worth of iscsi disk and presents them as
> 6 different NFS shares.  It is an active-active-active cluster with
> each node presenting a couple of shares.  It works pretty well.  I am
> doubting my decision to use NFS and am wondering if CIFS would be a
> better route.  Here are the NFS stats:
> 
> getattr	lookup	access	read	write	readdirplus
> 20%         16%	        7%	        44%	9%	1%
> 
> Each NFS node pushes about 65 MB/s so they are pretty busy.  It is a
> backup/recovery application so I would describe the I/O as lots of
> small reads/writes.
> 
> Any thoughts?
> 
Why are you looking to switch?

As always, the only way to really tell is to bench it out yourself. I
can tell you though that the Linux CIFS client doesn't parallelize
writes well at all and that will probably hobble your throughput
somewhat.

-- 
Jeff Layton <jlayton at samba.org>