[ Friday, February 25, 2000 ] Gregory Leblanc wrote:
> > Then, how much slower (not faster I guess :) Smart Array 221 would be
> > than SW-RAID (single P3-500)? And can I do all SA-221 maintaining from
> > Linux or do I need to reboot to dos? New official home
> > (ftp://ftp.compaq.com/pub/products/drivers/linux/) does not have too
> > much documentation..
>
> That sort of depends on what the server is doing. Software RAID performance
> is dependant on how many CPU cycles you have free. I.E. software RAID is
> probably BAD for DNS servers, and database servers.
2 things:
1) this brings up an interesting point about prioritization. Can someone
do tiobench runs with a totally idle machine and then with something
pegging the processors? (load avg = # of processors)
2) If the avg load on the machine is < 80% of (# of processors) you're
likely to have the spare cycles, even for DB and DNS servers. Depending
on access patterns and usage, even the most heavily pegged DB server
may have the spare cycles as current access patterns bottleneck the DB
activities at other places (disk, scsi bus, whatever)
A nice study of how load (both CPU and other I/O, like to a network PCI
GigE card) would be most enlightening.
James
