I/O、内存、网络性能优化命令 iostat , vmstat,netstat( 二 )


0 0 0 11456 4120 1 41 19 1 3 0 2 0 4 0 0 48 112 130 4 14 82
0 0 1 10132 4280 0 4 44 0 0 0 0 0 23 0 0 211 230 144 3 35 62
0 0 1 10132 4616 0 0 20 0 0 0 0 0 19 0 0 150 172 146 3 33 64
0 0 1 10132 5292 0 0 9 0 0 0 0 0 21 0 0 165 105 130 1 21 78




The fields of vmstat"s display are
procs
r in run queue
b blocked for resources I/O, paging etc.
w swapped

memory (in Kbytes)
swap - amount of swap space currently available
free - size of the free list

page ( in units per second).
re page reclaims - see -S option for how this field is modified.
mf minor faults - see -S option for how this field is modified.
pi kilobytes paged in
po kilobytes paged out
fr kilobytes freed
de anticipated short-term memory shortfall (Kbytes)
sr pages scanned by clock algorithm

disk ( operations per second )
There are slots for up to four disks, labeled with a single letter and number.
The letter indicates the type of disk (s = SCSI, i = IPI, etc) . The number is
the logical unit number.

faults
in (non clock) device interrupts
sy system calls
cs CPU context switches

cpu - breakdown of percentage usage of CPU time. On multiprocessors this is an a
verage across all processors.
us user time
sy system time
id idle time

结果和解决方案:

A. CPU issues:

下面几列需要被察看,以确定cpu是否有问题

Processes in the run queue (procs r)
User time (cpu us)
System time (cpu sy)
Idle time (cpu id)
procs cpu
r b w us sy id
0 0 0 4 14 82
0 0 1 3 35 62
0 0 1 3 33 64
0 0 1 1 21 78



问题情况:
1.) 如果processes in run queue (procs r)的数量远大于系统中cpu的数量,将会使系统便慢 。
2.) 如果这个数量是cpu的4倍的话,说明系统正面临cpu能力短缺,这将使系统运行速度大幅度降低
3.) 如果cpu的idle时间经常为0的话,或者系统占用时间(cpu sy)是用户占用时间(cpu us)两辈的话,系统面临缺少cpu资源

解决方案 :
解决这些情况,涉及到调整应用程序,使其能更有效的使用cpu,同时增加cpu的能力或数量 。

B. Memory Issues:
内存的瓶颈取决于scan rate (sr)。scan rate是每秒时钟对页的扫描 (he scan rate is the pages scanned by the clock algorithm per

second.)如果 scan rate (sr)一直大于200 pages每秒,这时就是内存短缺的现实 。

解决方案 :
1. 调整应用和服务器,使其能更好的使用memory和cache
2. 增加系统内存
3. Implement priority paging in s in pre Solaris 8 versions by adding line "set priority paging=1" in
/etc/system. Remove this line if upgrading from Solaris 7 to 8 & retaining old /etc/system file.

Network Statistics (netstat)

netstat通过选项来显示不通的网络相关的数据结构(netstat displays the contents of various network-related data structures

in depending on the options selected.)

语法 :

netstat

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