on 05:58 Thu 03 Feb, mcclnx mcc (mcclnx at yahoo.com.tw) wrote: > We have DELL R900 server with 128GB RAM (CENTOS 5.5)in it. This > server only have one application running and few people use it. > > Every week I ata least get one or two messages from monitor tool mail > to me say: > > Message=Memory Utilization is 92.02%, crossed warning (80) or critical > (90) threshold. > > Since server have 128 GB RAM and only 1 application. I really don't > belive that. Does there has some way can check memory utilitation ? Make sure your tool is reporting utilization less cache. As others have noted, the "-/+ buffers/cache" line in "free" output is what you're looking for. http://www.linuxatemyram.com/ If you've got sar (sysstat) installed and activated (read the manpage and /usr/share/doc/sysstat* materials if not), numerous system resource usages are logged every ten minutes. For memory usage: 'sar -r': 12:00:01 AM kbmemfree kbmemused %memused kbbuffers kbcached kbswpfree kbswpused %swpused kbswpcad 12:10:01 AM 45877732 3573788 7.23 208792 1948316 2097144 0 0.00 0 12:20:01 AM 45875572 3575948 7.23 208792 1948336 2097144 0 0.00 0 12:30:01 AM 45877120 3574400 7.23 208796 1948352 2097144 0 0.00 0 12:40:01 AM 45878352 3573168 7.23 208796 1948368 2097144 0 0.00 0 12:50:01 AM 45876080 3575440 7.23 208800 1948384 2097144 0 0.00 0 01:00:01 AM 45877244 3574276 7.23 208800 1948408 2097144 0 0.00 0 There are tools (NOT currently in CentOS) to graph/visualize these outputs as well. If you want per-process accounting, you can get that as well, but it'll cost you some performance overhead and a lot of set-up. -- Dr. Ed Morbius Chief Scientist Krell Power Systems Unlimited