iostat命令使用

是在sun网站上看到的，原文是e文，连接如下： http://www.adminschoice.com/docs/iostat_vmstat_netstat.htm Input Output statistics ( iostat ) iostat反映了终端、磁盘I/O情况和CPU活动。输出结果的第一行是从系统启动到现在为止的这段时间的结果，接下去的每一行是interval时 间段内的结果。Kernel里有一组计数器用来跟踪这些值。 iostat的默认参数是tdc(terminal, disk, and CPU)。如果任何其他的选项被指定，这个默认参数将被完全替代，例如，iostat -d将只反 映磁盘的统计结果。 语法: 基本语法： iostat <options> interval count option - 让你指定所需信息的设备，像磁盘、cpu或者终端(-d , -c , -t or -tdc ) 。x 选项给出了完整的统计结果（gives the extended statistic）。 interval - 在两个samples之间的时间（秒）。 count - 就是需要统计几次 例子： $ iostat -xtc 5 2 extended disk statistics tty cpu disk r/s w/s Kr/s Kw/s wait actv svc_t %w %b tin tout us sy wt id sd0 2.6 3.0 20.7 22.7 0.1 0.2 59.2 6 19 0 84 3 85 11 0 sd1 4.2 1.0 33.5 8.0 0.0 0.2 47.2 2 23 sd2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0 sd3 10.2 1.6 51.4 12.8 0.1 0.3 31.2 3 31 The fields have the following meanings: disk name of the disk r/s reads per second w/s writes per second Kr/s kilobytes read per second Kw/s kilobytes written per second wait average number of transactions waiting for service (Q length) actv average number of transactions actively being serviced (removed from the queue but not yet completed) %w percent of time there are transactions waiting for service (queue non-empty) %b percent of time the disk is busy (transactions in progress) Results and Solutions: 从iostat输出结果中需要注意的值： Reads/writes per second (r/s , w/s) Percentage busy (%b) Service time (svc_t) 如果磁盘显示长时间的高reads/writes，并且磁盘的percentage busy (%b)也远大于5%，同时average service time (svc_t)也远大于30 milliseconds，这以下的措施需要被执行： 1.)调整应用，令其使用磁盘i/o更加有效率，可以通过修改磁盘队列、使用应用服务器的cache 2.)将文件系统分布到2个或多个磁盘上，并使用volume manager/disksuite的条带化特点 3.) 增加系统参数值，如inode cache , ufs_ninode。Increase the system parameter values for inode cache , ufs_ninode , which is Number of inodes to be held in memory. Inodes are cached globally (for UFS), not on a per-file system basis 4.) 将文件系统移到更快的磁盘/控制器，或者用更好的设备来代替 Virtual Memory Statistics ( vmstat ) vmstat - vmstat反映了进程的虚拟内存、虚拟内存、磁盘、trap(是不是翻译成中断？？)和cpu的活动情况 在多cpu系统中，vmstat在输出结果中平均了cpu数量。For per-process statistics .如果没有选项，vmstat显示一行虚拟内存活动的概要 结果，是从系统启动时开始的。 语法: vmstat <options> interval count option - 让你指定所需的信息类型，例如 paging -p , cache -c ,.interrupt -i etc. 如果没有指定选项，将会显示进程、内存、页、磁盘、中断和cpu信息 interval - 同iostat count - 同iostat 例子 The following command displays a summary of what the system is doing every five seconds. example% vmstat 5 procs memory page disk faults cpu r b w swap free re mf pi p fr de sr s0 s1 s2 s3 in sy cs us sy id 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 <option/s> 多个选项可以同时使用 Options -a - displays the state of all sockets. -r - shows the system routing tables -i - gives statistics on a per-interface basis. -m - displays information from the network memory buffers. On Solaris, this shows statistics forSTREAMS -p [proto] - retrieves statistics for the specified protocol -s - shows per-protocol statistics. (some implementations allow -ss to remove fileds with a value of 0 (zero) from the display.) -D - display the status of DHCP configured interfaces. <