performance tuning
Performance Tools includeps
show processes# ps PID TTY TIME CMD 30138 pts/0 00:00:01 bash 2354 pts/0 00:00:00 ps
pstree
show process tree# pstree -cpl init(1)- -crond(1476) |-gpm(1456) |-httpd(1519)- -httpd(1701) | |-httpd(17543) | |-httpd(17545) | |-sh(1700) | |-sh(1705) | |-sh(1706) | |-sh(1707) | `-sh(1708) |-keventd(2) |-khubd(83) |-kjournald(16) |-kjournald(270) |-kjournald(271) |-klogd(1175) |-lockd(13904)
top
show top processestop - 17:22:53 up 7:23, 4 users, load average: 0.11, 0.31, 0.48 Tasks: 110 total, 1 running, 108 sleeping, 0 stopped, 1 zombie Cpu(s): 4.7% us, 11.3% sy, 0.0% ni, 82.0% id, 2.0% wa, 0.0% hi, 0.0% si Mem: 1027228k total, 976288k used, 50940k free, 9564k buffers Swap: 2048276k total, 29560k used, 2018716k free, 518336k cached PID USER PR NI VIRT RES SHR S %CPU %MEM TIME COMMAND 3117 root 15 0 200m 59m 11m S 2.0 5.9 15:57.03 X 1 root 16 0 2228 548 472 S 0.0 0.1 0:00.51 init 2 root 34 19 0 0 0 S 0.0 0.0 0:00.00 ksoftirqd/0
you can get top to refresh every 5 seconds by entering "s" followed by ".2" or even 5 times a second by entering "s" followed by ".2" !
free
show free memory spacetotal used free shared buffers cached Mem: 191244 188188 3056 424 7932 65344 -/ buffers/cache: 114912 76332 Swap: 1534196 109212 1424984
vmstat
vm statsprocs memory swap io system cpu r b swpd free buff cache si so bi bo in cs us sy id wa 2 1 0 8796 582176 386188 0 0 31 66 78 52 3 12 70 15
mpstat
mp statsLinux 2.6.9-11.EL (pc66.rentokil.com) 20/09/05 12:27:45 CPU %user %nice %system %iowait %irq %soft %idle intr/s 12:27:45 all 9.75 0.91 30.61 7.37 0.26 0.06 51.05 1120.40
iostat
io statsLinux 2.4.21-32.EL (www.osde.info) 19/09/05 avg-cpu: %user %nice %sys %iowait %idle 3.03 0.00 14.91 14.15 67.92 Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn sda 0.49 2.77 6.29 1266680 2873570 sda1 0.00 0.00 0.00 358 98 sda2 0.49 2.77 6.29 1265834 2873472 sda3 0.00 0.00 0.00 168 0 sdb 8.54 1418.14 372.91 647812930 170348368 sdb1 8.54 1418.14 372.91 647812810 170348368 sdc 7.34 1693.89 77.13 773773986 35232480 sdc1 7.34 1693.89 77.13 773773866 35232480 sdd 228.14 3521.39 7006.04 1608582338 3200387128 sdd1 228.14 3521.38 7006.04 1608582218 3200387128
sar
show system activityLinux 2.6.9-11.EL (www.osde.info) 19/09/05 16:10:01 CPU %user %nice %system %iowait %idle 16:20:01 all 12.92 0.02 10.96 0.95 75.16 16:30:01 all 8.31 0.02 9.72 1.16 80.79 16:40:01 all 12.07 0.03 10.17 0.45 77.27 16:50:01 all 16.61 0.02 11.86 1.15 70.36 17:00:01 all 10.56 0.02 14.22 1.82 73.38 17:10:01 all 13.95 0.02 10.90 0.99 74.14 17:20:01 all 16.23 0.02 11.12 0.66 71.96 Average: all 12.95 0.02 11.28 1.03 74.72
The last two are not installed by default so use the RedHatPackageManager to install the SysStat package which provides the sar and iostat commands for Linux. Sar and iostat enable system monitoring of disk, network, and other IO activity.
CentOS 3.x
rpm -ivh /mnt/temp/RedHat/RPMS/sysstat-5.0.5-5.rhel3.i386.rpm
CentOS 4.x
rpm -ivh /media/cdrecorder/CentOS/RPMS/sysstat-5.0.5-1.i386.rpm
load testing
Use a lot of CPU$ while true ; do true ; done &
then do a
$ top
see 100% cpu then
$ kill %1
REFERRERS
SysAdmin
