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是在sun网站上看到的,原文是e文,连接如下:\r\nhttp://www.adminschoice.com/docs/iostat_vmstat_netstat.htm\r\n\r\n大概翻译了一下,总觉得好像以前哪位大大贴过类似的\r\n不管了,觉得有点用,大家一起看看\r\n翻译得不好,见笑了……如果有错,请指正哦,先谢了\r\n\r\nInput Output statistics ( iostat )\r\n\r\n 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\r\n\r\n间段内的结果。Kernel里有一组计数器用来跟踪这些值。\r\n 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\r\n\r\n映磁盘的统计结果。\r\n\r\n语法:\r\n\r\n基本语法: iostat <options>; interval count\r\n\r\noption - 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 \r\n\r\nstatistic)。\r\n\r\ninterval - 在两个samples之间的时间(秒)。\r\n\r\ncount - 就是需要统计几次\r\n\r\n例子:\r\n\r\n $ iostat -xtc 5 2\r\n extended disk statistics tty cpu\r\n disk r/s w/s Kr/s Kw/s wait actv svc_t %w %b tin tout us sy wt id\r\n sd0 2.6 3.0 20.7 22.7 0.1 0.2 59.2 6 19 0 84 3 85 11 0\r\n sd1 4.2 1.0 33.5 8.0 0.0 0.2 47.2 2 23\r\n sd2 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0 0\r\n sd3 10.2 1.6 51.4 12.8 0.1 0.3 31.2 3 31\r\n \r\n\r\n The fields have the following meanings:\r\n\r\n disk name of the disk\r\n r/s reads per second\r\n w/s writes per second\r\n Kr/s kilobytes read per second\r\n Kw/s kilobytes written per second\r\n wait average number of transactions waiting for service (Q length)\r\n actv average number of transactions actively \r\n being serviced (removed from the\r\n queue but not yet\r\n completed)\r\n %w percent of time there are transactions waiting\r\n for service (queue non-empty)\r\n %b percent of time the disk is busy (transactions\r\n in progress)\r\n \r\n \r\n\r\n \r\nResults and Solutions:\r\n\r\n从iostat输出结果中需要注意的值:\r\n\r\nReads/writes per second (r/s , w/s) \r\nPercentage busy (%b) \r\nService time (svc_t) \r\n\r\n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 \r\n\r\nmilliseconds,这以下的措施需要被执行:\r\n1.)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 \r\n\r\n2.)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\r\n\r\n3.) 增加系统参数值,如inode cache , ufs_ninode。Increase the system parameter values for inode cache , ufs_ninode , which \r\n\r\nis Number of inodes to be held in memory. Inodes are cached globally (for UFS), not on a per-file system basis \r\n\r\n4.) 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\r\n\r\n 还有两段等会翻好了再贴…… |
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