挺详细的。是好东东。
iostat的默认参数是td默认参数将被完全替代,例c(terminal, disk, and CPU)。如,iostat -d将只反 映磁盘的如果任何其他的选项被指定,这个统计结果。 语法: 基本语法: iostat interval count option - 让你指定所。x 选项给出了完整的统计需信息的设备,像磁盘、cpu或结果(gives the extended 者终端(-d , -c , -t or -tdc ) 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 tintout 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/writ同时average service time (svc_t)也远es,并且磁盘的percentage busy (%b)也远大于5%,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cache 有效率,可以通过修改磁盘队列、使用应用服务器的 2.)将文件系统分布到2个或多个磁盘上,并使用volumemanager/disksuite的条带化特点 3.) 增加系统参数值,values for inode cache ,如inode cache , ufs_ninode。ufs_ninode , which Increase the system parameter is Number of inodes to be held iUFS), not on a per-file system basisn memory. Inodes are cached globally (for 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 vmstat - vmstat反映?)和cpu的活动情况 了进程的虚拟内存、虚拟内存、磁盘、trap(是不是翻译成中断? 在多cpu系统中,vmsta果没有选项,vmstat显示一t在输出结果中平均了cpu数量。行虚拟内存活动的概要 For per-process statistics .如 结果,是从系统启动时开始的。 语法: vmstat interval count option - 让你指定所需的信息类型etc. ,例如 paging -p , cache -c ,.interrupt -i 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 whatthe 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 desr 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 0 444 0 0 0 0 0 23 0 0 211 230144 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 09 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 memoryshortfall (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 indicatesthe 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 pan a ercentage usage of CPU time.On multiprocessors this is verage across all p