View Io data with iostat

In Linux, performance problems occur. Generally, we can use top, iostat, free, vmstat, and other commands to locate the problem. Iostat can provide us with a wealth of Io status data.

$ Iostat-D-K 1 10

The-D parameter indicates that the Usage Status of the device (Disk) is displayed.-K indicates that kilobytes is used as the unit of block usage. 1 10 indicates that the data is refreshed every one second, 10 times in total.

TPS: the number of transmissions per second (indicate the number of transfers per second that were issued to the device .). "One transmission" means "one I/O Request ". Multiple logical requests may be merged into one I/O Request ". The size of a "one-time transmission" request is unknown.

Kb_read/s: the amount of data read from the device (drive expressed) per second; kb_wrtn/s: the amount of data written to the device (drive expressed) per second; kb_read: the total amount of data read; kb_wrtn: the total amount of data written. These units are kilobytes.

Common usage:

$ Iostat-D-K 1 10 # view TPS and throughput Information

Iostat-D-X-K 1 10 # view device usage (% util), response time (await)

Iostat-C 1 10 # view CPU status

Original article:

Http://www.orczhou.com/index.php/2010/03/iostat-detail/

Http://www.cnblogs.com/mfryf/archive/2012/03/12/2392000.html