Justin S. Leitgeb <[EMAIL PROTECTED]> wrote: >> On Thu, 08 Feb 2007 16:18:44 -0500 >> "Justin S. Leitgeb" <[EMAIL PROTECTED]> wrote: >>>> That being said, since deleuze is the AFS server, I have the cache >>>> set to use 64MB of RAM instead of larger disk cache. Mire should >>>> probably have an on-disk cache setup on the order of several GBs. >>>> Ideally, /var/cache/openafs should be a dedicated partition. >>>> >>> Is mire still going to be run with software RAID? If this is the >>> case, perhaps you'll want to establish a partition that is not >>> redundant for caching purposes. Fyodor had software RAID and disk >>> i/o was often a source of bottlenecks. >> >> The problem was only during backups, and due to the algorithm used >> in rsync, which wasn't able to cope with a huge number of files that >> we wanted it to sync in the single run. > > I think that the problems were also visible during the runs of > spamassassin. Maybe this isn't an issue, but my concern was that > software RAID generally seems to be a relatively slow medium that > wouldn't really give us any performance advantage when used for AFS > caching compared to the direct disk access of another machine with a > RAID 10 set via a fast network. To the contrary, I think that there > is a good chance that it would introduce additional bottlenecks. > > Obviously you could do some performance benchmarks to be more sure > about this, it just seemed to me that it was certainly not settled > that the caching mechanism of AFS was going to help us here given our > particular hardware configuration.
I would strongly suggest putting the AFS vice paritions on seperate physical disks from the rest of the system. However, I'm not sure if that is possible with the current hardware. Also, does spamassassin run at the system level or per-user? I imagine there could be I/O gains running it only at the system layer and tagging spam there and using exim filters to sort it out. <<CDC _______________________________________________ HCoop-SysAdmin mailing list [email protected] http://hcoop.net/cgi-bin/mailman/listinfo/hcoop-sysadmin
