日期:2014-05-16  浏览次数:20645 次

linux分析、诊断及调优必备的“杀器”之二

先说明下,之所以同类内容分成多篇文章,不是为了凑篇数,而是为了便于自己和大家阅读,下面继续:

7、sar

The sar command is used to collect, report, and save system activity information. The sar command consists of three applications: sar, which displays the data, and sa1 and sa2, which are used for collecting and storing the data. The sar tool features a wide range of options so be sure to check the man page for it. The sar utility is part of the sysstat package.

To accomplish this, add the lines to /etc/crontab.Keep in mind that a default cron job running sar daily is set up automatically after installing sar on your system.

Example of starting automatic log reporting with cron

-------------------------------------------------------------------------

# 8am-7pm activity reports every 10 minutes during weekdays.
*/10 8-18 * * 1-5 /usr/lib/sa/sa1 600 6 &
# 7pm-8am activity reports every an hour during weekdays.
0 19-7 * * 1-5 /usr/lib/sa/sa1 &
# Activity reports every an hour on Saturday and Sunday.
0 * * * 0,6 /usr/lib/sa/sa1 &
# Daily summary prepared at 19:05
5 19 * * * /usr/lib/sa/sa2 -A &

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The raw data for the sar tool is stored under /var/log/sa/ where the various files represent the days of the respective month. To examine your results, select the weekday of the month and he requested performance data. For example, to display the network counters from the 21st, use the command sar -n DEV -f sa21 and pipe it to less as in the following example:

---------------------------------------------------------------------------

root# sar -n DEV -f sa21 | less
Linux 2.6.9-5.ELsmp (linux.itso.ral.ibm.com) 04/21/2005
12:00:01 AM IFACE rxpck/s txpck/s rxbyt/s txbyt/s rxcmp/s txcmp/s rxmcst/s
12:10:01 AM lo 0.00 0.00 0.00 0.00 0.00 0.00 0.00
12:10:01 AM eth0 1.80 0.00 247.89 0.00 0.00 0.00 0.00
12:10:01 AM eth1 0.00 0.00 0.00 0.00 0.00 0.00 0.00

---------------------------------------------------------------------------

You can also use sar to run near-real-time reporting from the command line as the following example:
---------------------------------------------------------------------------

root# sar -u 3 10
Linux 2.4.21-9.0.3.EL (x232) 05/22/2004
02:10:40 PM CPU %user %nice %system %idle
02:10:43 PM all 0.00 0.00 0.00 100.00
02:10:46 PM all 0.33 0.00 0.00 99.67
02:10:49 PM all 0.00 0.00 0.00 100.00
02:10:52 PM all 7.14 0.00 18.57 74.29
02:10:55 PM all 71.43 0.00 28.57 0.00
02:10:58 PM all 0.00 0.00 100.00 0.00
02:11:01 PM all 0.00 0.00 0.00 0.00
02:11:04 PM all 0.00 0.00 100.00 0.00
02:11:07 PM all 50.00 0.00 50.00 0.00
02:11:10 PM all 0.00 0.00 100.00 0.00
Average: all 1.62 0.00 3.33 95.06

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From the collected data, you see a detailed overview of CPU utilization (%user, %nice,%system, %idle), memory paging, network I/O and transfer statistics, process creation activity, activity for block devices, and interrupts/second over time.

8、mpstat

The mpstat command is used to report the activities of each of the available CPUs on a multiprocessor server. Global average activities among all CPUs are also reported. The mpstat utility is part of the sysstat package.for example:

root# mpstat -P ALL
Linux 2.6.9-5.ELsmp (linux.itso.ral.ibm.com) 04/22/2005
03:19:21 PM       CPU         %user         %nice         %system        %iowait            %irq              %soft              %idle              intr/s
03:19:21 PM   &nb