Hello ,

I am using openafs 1.4.1 with linux 2.6.16.16. Afsd runs with -stat 4000 -dcache 4000 -daemons 6 -volumes 256 -files 50000 -chunksize 20. The client system serves as an anonymous ftp server, with around 80 ftp server instances concurrently accessing various files on afs. A particular popular file X is around 2.4 GB large. Other popular files have sizes starting from 2 Mbytes up to 700. A test when the afsd has just started with just one ftp server instance transferring file X achieves speeds 10-20 MB/sec, with 12-15 being the average. Repeated transfers of the same file again with one ftp client exhibit more or less the same results. Test was made with wget and lftp. Pure-ftpd is the ftp server software. When around 80 ftp server instances access afs performance drops to around 3-60 KB/sec for each one. Load average exceeds 20 and can reach 80. Disk activity is quiet intensive but the system is unable to push more than 2.5 MB/sec to the network. Killing all ftp server instances and again testing with only one improves things a bit: speed flactuates between
1-7 MB/sec. Restarting afsd brings performance back to 10+ MB/sec.
I switched the afs cache from one devoted ata100 disk to a 4 disk ata100 striping raid but nothing changed. AFS server is p4@ 2.6GHz, 1GB ram 4 sata disks on striping raid. Its load rarely exceeds 0.5. The ftp server is p4 celeron @ 2GHz, 512MB ram, afs cache tested on single disk and 4 disk raid. It does not consume any of its swap at all.All are connected at the same Gigabit switch. The clients accessing the ftp server are mostly DSL users and when afs is not involved they usually peek at around 3.5 MB/sec.

        Can anyone think of anything I can do to improve performance?

        Best regards ,

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Dimitris Zilaskos

Department of Physics @ Aristotle University of Thessaloniki , Greece
PGP key : http://tassadar.physics.auth.gr/~dzila/pgp_public_key.asc
          http://egnatia.ee.auth.gr/~dzila/pgp_public_key.asc
MD5sum  : de2bd8f73d545f0e4caf3096894ad83f  pgp_public_key.asc
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