Shulou(Shulou.com)06/01 Report--

Vmstat (included in the system): use the wmstat command to monitor the memory information, process status, CPU activity and so on of the operating system.

Usage: example: # vmstat 3 5-> executed every 3 seconds for a total of 5 times

Note: the first row of data is the average since the system was started, and the other lines are the average of the interval time set when running the vmstat command.

R column: length of ready queue, number of tasks being processed by or waiting for CPU (number of processes). The normal value of r is less than the number of cores of cpu. If it is often greater than the number of cores of cpu, it means that the task pressure of cpu is relatively heavy.

B column: the number of uninterruptible processes (IO operations in progress). The reference standard is the number of cores less than cpu, and often greater than the number of cores of cpu indicates that the pressure on cpu tasks is relatively heavy.

Buff column: cache when reading and writing to block devices (disks)

Cache column: the cache for reading and writing files. If this value is large, it means that more files are cached.

Si column: number of swaps from memory to disk

So column: the number of calls from memory to disk. If si,so is used, the system is out of memory.

Bi column: the total amount of data read from the block device (that is, the read disk size); in blocks / s, because the block size in Linux is 1KB, which is equivalent to KB/s

Bo column: the total amount of data written to the block device (that is, the size of the write operation); in blocks / s, because the block size in Linux is 1KB, which is equivalent to KB/s

In column: the number of interrupts per second for the device; is the total number of interrupts, including hard and soft interrupts

Cs column: the number of context switches generated per second

Us column: percentage of CPU consumed by user processes

Sy column: percentage of CPU consumed by kernel processes

Id column: percentage of CPU idle

Wa column: percentage of CPU occupied by IO waiting (this value is normally less than 20%. If it is greater than 50% for a long time, it indicates that there is a serious problem with disk IO)

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