Additions:
$ while true ; do true ; done &
then do a
$ top
see 100% cpu then
$ kill %1
Deletions:
$ while true ; do true ; done
Use a lot of CPU even after you have logged out !
$ nohup bash -c "while true ; do true ; done" &
Additions:
performance tuning
ps
show processes
pstree
show process tree
|-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 processes
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 space
total used free shared buffers cached
vmstat
vm stats
mpstat
mp stats
iostat
io stats
3.03 0.00 14.91 14.15 67.92
sar
show system activity
load testing
Use a lot of CPU
$ while true ; do true ; done
Use a lot of CPU even after you have logged out !
$ nohup bash -c "while true ; do true ; done" &
Deletions:
- ps
- pstree
|-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
Did you know you can refresh top 5 times a second by entering "s" followed by ".2"
- free
total used free shared buffers cached
- vmstat
- mpstat
- iostat
3.03 0.00 14.91 14.15 67.92
- sar
Additions:
init(1)- -crond(1476)
|-httpd(1519)- -httpd(1701)
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME COMMAND
-/ buffers/cache: 114912 76332
Deletions:
init(1)-+-crond(1476)
|-httpd(1519)-+-httpd(1701)
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
-/+ buffers/cache: 114912 76332
Additions:
# 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)
Deletions:
# pstree -c -p
init(1)-+-
MegaServ(1219)
|-crond(1546)
|-dcd_tmr_thread(1667)
|-dcevt32d(1788)
dcevt32d(1789)
dcevt32d(1790)
|-dcsnmp32d(1777)
dcsnmp32d(1778)-+-dcsnmp32d(1779)
| `-dcsnmp32d(1780)
|-dcstor32d(1759)
dcstor32d(1760)-+-dcstor32d(1761)
| |-dcstor32d(1766)
| |-dcstor32d(1767)
| |-dcstor32d(1768)
| `-dcstor32d(1769)
|-gpm(1528)
|-httpd(1582)-+-httpd(1604)
| |-httpd(9712)
| `-httpd(15069)
Additions:
Additions:
# ps
# pstree -c -p
init(1)-+-
MegaServ(1219)
|-crond(1546)
|-dcd_tmr_thread(1667)
|-dcevt32d(1788)
dcevt32d(1789)
dcevt32d(1790)
|-dcsnmp32d(1777)
dcsnmp32d(1778)-+-dcsnmp32d(1779)
| `-dcsnmp32d(1780)
|-dcstor32d(1759)
dcstor32d(1760)-+-dcstor32d(1761)
| |-dcstor32d(1766)
| |-dcstor32d(1767)
| |-dcstor32d(1768)
| `-dcstor32d(1769)
|-gpm(1528)
|-httpd(1582)-+-httpd(1604)
| |-httpd(9712)
| `-httpd(15069)
total used free shared buffers cached
Mem: 191244 188188 3056 424 7932 65344
-/+ buffers/cache: 114912 76332
Swap: 1534196 109212 1424984
Linux 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
Deletions:
Additions:
PID TTY TIME CMD
30138 pts/0 00:00:01 bash
2354 pts/0 00:00:00 ps
top - 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
Did you know you can refresh top 5 times a second by entering "s" followed by ".2"
procs 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
Linux 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
Linux 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 oldest known version of this page was edited on
2005-09-19 11:25:31 by WikkaWiki (unregistered user)
Performance Tools include
- ps
- top
- free
- vmstat
- iostat
- sar
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