On Wed, 2006-03-01 at 16:34 -0500, Lamar Owen wrote: > On Wednesday 01 March 2006 13:45, Peter Farrow wrote: > > You need to check out whether the system is waiting on IO, on the > > version of top on Centos 4.2 it doesn't show IO wait on the display, but > > on the RH enterprise shipping version it does. > > > A load average of 9 is getting high, you expect would services like > > sendmail to stop listening once the system load average gets to 12. I generally try to keep max load to no more than 2 - 2.5 times the number of processors in the machine ... so that is 8-10 for a quad processor machine ... 4-5 for a dual processor and 2-3 for a single processor machine. That assumes that there is actual IO and load on the processes and not a high load number with lots of idle time. So, those numbers and ~100% CPU utilization is what I shoot for as maximums. I'm sure other people have different goal numbers. > As a data point, on my Sun E6500 during load testing a few months back, under > Aurora SPARC Linux (I would expect similar performance from CentOS SPARC) I > was pulling a load average of 250+ with little interactive degradation > (command line mode). The E6500 had 14 CPU's and 16GB of RAM at the time, and > was serving an ab load (apache bench) of 256 concurrent requests to a Koha > integrated library system backend, over a total of 2.5 million requests. > Every page hit the database at least twice, from Perl. System at that load > average was serving 6 pages per second; at a concurrency of 1, system served > 4 pages per second, so performance increased as load did. I would have hit > it with more concurrency, but httpd was compiled with a 256 connection max > limit. -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 189 bytes Desc: This is a digitally signed message part URL: <http://lists.centos.org/pipermail/centos/attachments/20060301/b2bbe52e/attachment-0004.sig>