linux分析、诊断及调优必备的“杀器”之二

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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

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# 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:

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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

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You can also use sar to run near-real-time reporting from the command line as the following example:
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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 all 0.03 0.00 0.34 0.06 0.02 0.08 99.47 1124.22
03:19:21 PM 0 0.03 0.00 0.33 0.03 0.04 0.15 99.43 612.12
03:19:21 PM 1 0.03 0.00 0.36 0.10 0.01 0.01 99.51 512.09

root# mpstat -P ALL 1 2
Linux 2.6.9-5.ELsmp (linux.itso.ral.ibm.com) 04/22/2005
03:31:51 PM CPU %user %nice %system %iowait %irq %soft %idle intr/s
03:31:52 PM all 0.00 0.00 0.00 0.00 0.00 0.00 100.00 1018.81
03:31:52 PM 0 0.00 0.00 0.00 0.00 0.00 0.00 100.00 991.09
03:31:52 PM 1 0.00 0.00 0.00 0.00 0.00 0.00 99.01 27.72

Average: CPU %user %nice %system %iowait %irq %soft %idle intr/s
Average: all 0.00 0.00 0.00 0.00 0.00 0.00 100.00 1031.89
Average: 0 0.00 0.00 0.00 0.00 0.00 0.00 100.00 795.68
Average: 1 0.00 0.00 0.00 0.00 0.00 0.00 99.67 236.54

For the complete syntax of the mpstat command, issue:
mpstat -?

9、numastat

With Non-Uniform Memory Architecture (NUMA) systems such as the IBM System x 3950,NUMA architectures have become mainstream in enterprise data centers. However, NUMA systems introduce new challenges to the performance tuning process. Topics such as memory locality were of no interest until NUMA systems arrived. Luckily, Enterprise Linux distributions provide a tool for monitoring the behavior of NUMA architectures. The numastat command provides information about the ratio of local versus remote memory usage and the overall memory configuration of all nodes. Failed allocations of local memory, as displayed in the numa_miss column and allocations of remote memory (slower memory), as displayed in the numa_foreign column should be investigated. Excessive allocation of remote memory will increase system latency and likely decrease overall performance. Binding processes to a node with the memory map in the local RAM will most likely improve performance.for example:

root# numastat
node1 node0
numa_hit 76557759 92126519
numa_miss 30772308 30827638
numa_foreign 30827638 30772308
interleave_hit 106507 103832
local_node 76502227 92086995
other_node 30827840 30867162

10、pmap

The pmap command reports the amount of memory that one or more processes are using. You can use this tool to determine which processes on the server are being allocated memory and whether this amount of memory is a cause of memory bottlenecks. For detailed information,use pmap -d option.

pmap -d <pid>

for example,

root# pmap -d 1
1: init [3]
Address Kbytes Mode Offset Device Mapping
0000000000400000 36 r-x-- 0000000000000000 0fd:00000 init
0000000000508000 8 rw--- 0000000000008000 0fd:00000 init
000000000050a000 132 rwx-- 000000000050a000 000:00000 [ anon ]
0000002a95556000 4 rw--- 0000002a95556000 000:00000 [ anon ]
0000002a95574000 8 rw--- 0000002a95574000 000:00000 [ anon ]
00000030c3000000 84 r-x-- 0000000000000000 0fd:00000 ld-2.3.4.so
00000030c3114000 8 rw--- 0000000000014000 0fd:00000 ld-2.3.4.so
00000030c3200000 1196 r-x-- 0000000000000000 0fd:00000 libc-2.3.4.so
00000030c332b000 1024 ----- 000000000012b000 0fd:00000 libc-2.3.4.so
00000030c342b000 8 r---- 000000000012b000 0fd:00000 libc-2.3.4.so
00000030c342d000 12 rw--- 000000000012d000 0fd:00000 libc-2.3.4.so
00000030c3430000 16 rw--- 00000030c3430000 000:00000 [ anon ]
00000030c3700000 56 r-x-- 0000000000000000 0fd:00000 libsepol.so.1
00000030c370e000 1020 ----- 000000000000e000 0fd:00000 libsepol.so.1
00000030c380d000 4 rw--- 000000000000d000 0fd:00000 libsepol.so.1
00000030c380e000 32 rw--- 00000030c380e000 000:00000 [ anon ]
00000030c4500000 56 r-x-- 0000000000000000 0fd:00000 libselinux.so.1
00000030c450e000 1024 ----- 000000000000e000 0fd:00000 libselinux.so.1
00000030c460e000 4 rw--- 000000000000e000 0fd:00000 libselinux.so.1
00000030c460f000 4 rw--- 00000030c460f000 000:00000 [ anon ]
0000007fbfffc000 16 rw--- 0000007fbfffc000 000:00000 [ stack ]
ffffffffff600000 8192 ----- 0000000000000000 000:00000 [ anon ]
mapped: 12944K writeable/private: 248K shared: 0K

For the complete syntax of the pmap command, issue:
pmap -?

11、netstat

常用选项：

-a Show all socket information
-r Show routing information
-i Show network interface statistics
-s Show network protocol statistics

例子：

root# netstat -natuw
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address Foreign Address State
tcp 0 0 0.0.0.0:111 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:2207 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:36285 127.0.0.1:12865 TIME_WAIT
tcp 0 0 10.0.0.5:37322 10.0.0.4:33932 TIME_WAIT
tcp 0 1 10.0.0.5:55351 10.0.0.4:33932 SYN_SENT
tcp 0 1 10.0.0.5:55350 10.0.0.4:33932 LAST_ACK
tcp 0 0 10.0.0.5:64093 10.0.0.4:33932 TIME_WAIT
tcp 0 0 10.0.0.5:35122 10.0.0.4:12865 ESTABLISHED
tcp 0 0 10.0.0.5:17318 10.0.0.4:33932 TIME_WAIT
tcp 0 0 :::22 :::* LISTEN
tcp 0 2056 ::ffff:192.168.0.254:22 ::ffff:192.168.0.1:3020 ESTABLISHED
udp 0 0 0.0.0.0:111 0.0.0.0:*
udp 0 0 0.0.0.0:631 0.0.0.0:*
udp 0 0 :::5353 :::*

输出列说明：

Proto:The protocol (tcp, udp, raw) used by the socket.
Recv-Q:The count of bytes not copied by the user program connected to this socket.
Send-Q:The count of bytes not acknowledged by the remote host.
Local Address:Address and port number of the local end of the socket. Unless the --numeric (-n) option is specified, the socket address is resolved to its canonical host name (FQDN), and the port number is translated into the corresponding service name.
Foreign Address:Address and port number of the remote end of the socket.
State:The state of the socket. Since there are no states in raw mode and usually no states used in UDP, this column may be left blank.

至此，已经介绍了linux上常用的工具，此外，还有一些使用频率较低或者针对某个方面更专业的工具，例如：iptraf,tcpdump / ethereal,nmon,strace等，这了不再一一详述，仅供大家参考学习，禁止转载。