CIFS read-ahead

[David Collier-Brown -- Customer Engineering]

   I have done some work in this area, primarily to deal
with filesystems which want quite large, aligned reads.
Notably RAID disk arrays!
   Can you describe your application to us? The cache read
code **might** address your problem.

--dave

Nicholas M. Kirsch wrote:
> I have two W2k3 machines, on GigE, one with a 2GB ramdisk acting as a
> server, one as a client. Try as I might, I cannot achieve more than about
> 250 MBs in a single-stream sequential read -- which I imagine can be
> blamed on latency. I have heard rumours of the ability to enable
> read-ahead for CIFS clients -- is this possible, or just a rumour? And if
> possible, can anyone offer some tips?
> 
> Of course, I have tried an identical configuration with FreeBSD and Samba
> 3.0 acting as the server, with the same speed as the result. Both machines
> are quite powerful, and I can achieve almost twice the throughput with
> NFS. I was told that NFS does aggressive read-ahead, and this was
> responsible for the difference.
> 
> If Samba cannot currently support read-ahead, but CIFS clients can be made
> to do so, I am interested in adding said support to Samba.
> 
> Thank you.
> 
> Nicholas Kirsch <nkirsch at isilon.com>
> Applications Developer, Isilon Systems Inc.
> 
> http://www.isilon.com/
> 
> 


-- 
David Collier-Brown,           | Always do right. This will gratify
Sun Microsystems DCMO          | some people and astonish the rest.
Toronto, Ontario               |
(905) 415-2849 or x52849       | davecb at canada.sun.com