[OpenAFS] OpenAFS Client Optimization

[Jeffrey Altman]

Performance characteristics depend on a variety of things.
The OpenAFS for Windows architecture is based upon an SMB
gateway model.  As a result an inability to pipeline operations
when there is only a single CPU has a significant impact.

The Microsoft SMB redirector has a max throughput of 56/MBs
on 32-bit XP and 64MB/sec on 64-bit Vista.

Throughput on gigabit networks using 1.5.59 with a 32-bit XP dual cpu
system with 1.4.8 file servers:

  (MB/sec)               Crypt On 	Crypt Off
  Write                     3.9            15.7
  Read (uncached)	   15.8            31.0
  Read (cached)            55.3            55.3

Reading a 4GB file will always be larger than the cache size on
32- bit Windows.  For 64-bit Windows you can increase the cache
size to many tens of GBs in size.  If you know you will predominantly
reading very large files in a sequential manner then you can increase
the chunksize used for FetchData/StoreData file server operations.

The performance of your file servers matter.  If they are slow
reading from or writing to disk it is going to slow down the clients
considerably.

Appendix A of the release notes describes all of the settings
that are available to you to adjust.   The values that are used
by default are appropriate for a random client with long round trip
times and limited bandwidth.

Jeffrey Altman

Claudio Prono wrote:
> Hi to all,
> 
> Someone can help me optimizing OpenAFS for Windows Client side? I have
> now a write rate of about 5000 Kbytes/sec, and a read rate of about 8000
> Kbytes/sec on a large file like 4 Gb. There is any way to increase that
> speed?
> 
> Cordially,
> 
> Claudio Prono.
>