AW: [OpenAFS] Severe Performance Issue with SCSI!

[Rubino Geiß]

We are checking this with our infrastructure guys, but so far we believe
that the switches as well as our network is doing all right (that is
duplex). 

Besides, we did the benchmark on different ports and segments of our
network -- and the AFS server with IDE drives _are_ fast.

Got anyone any further ideas, please :)

thanks and bye, Rubino

-----Ursprüngliche Nachricht-----
Von: Mitch Collinsworth [mailto:mitch@ccmr.cornell.edu] 
Gesendet: Donnerstag, 1. August 2002 16:35
An: Rubino Geiß
Cc: openafs-info@openafs.org; Bernd Traub (Bernd Traub)
Betreff: Re: [OpenAFS] Severe Performance Issue with SCSI!



A bit of a long-shot, but have you checked that your network duplex
settings match between the ethernet switch and the network adapter in
your SCSI machine?  A duplex mismatch will manifest in just the symptoms
you describe.

-Mitch

On Wed, 31 Jul 2002, [iso-8859-1] Rubino Geiß wrote:

> Hi all,
>
> what do you know about SCSI and OpenAFS performance?
>
> Our main server is a SCSI system with 6 disk (10k RPM, 32GB, 160 LDV) 
> on 2  Adaptec controllers. This setup is 2-4 times slower than a 
> similar system using IDE-drives (5,4kRPM, 40GB).
>
> I have already tested several other SCSI disk and host adapters along 
> with different computers and several version of Redhat Linux (7.1, 
> 7.2, 7.3). All I get out of these experiments is the fact, that 
> OpenAFS crawls if you use SCSI. Even RAID 1 and 2 and 5 (all tested) 
> doesn't help.
>
> Some AlphaServer, Tru64 UNIX 5.1 (IBM AFS) seems to perform well even 
> with  SCSI; actually this nearly 10 year old machine 10MBit interface 
> is even as fast as our fastest IDE-server running OpenAFS.
>
> Our LAN is a switched 100 MBit Ethernet.
>
> The test case is derived from our main application: compiler 
> construction. That is touching and reading many small files. Building 
> many rather small temporary files and directories.
>
> Your help is very appreciated.
>
> Thank you, Rubino
>
>
> --
> Rubino Geiss, Universitaet Karlsruhe, IPD Goos
> Postfach 6980, D-76128 Karlsruhe, GERMANY
> Adenauerring 20a, 50.41 (AVG), Zi. 235 
> rubino@ipd.info.uni-karlsruhe.de
> Tel: (+49) 721 / 608-8352
> Fax: (+49) 721 / 30047
>
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