Monitoring paging and swapping
In this recipe, we are going to use the sar and vmstat commands with options to monitor paging and swapping operations.
Getting ready
It is necessary to monitor the amount of paging and swapping happening on the operating system. Paging occurs when a part of the operating system process gets transferred from physical memory to disk, or is read back from physical memory to disk. Swapping occurs when an entire process gets transferred to disk, from physical memory to disk, or is read back into physical memory from disk. Depending on the system, either paging or swapping could be an issue. If paging is occurring normally, and if you see a trend of heavy swapping, then the issue could be related to insufficient memory or sometimes the issue could be related to disk as well. If the system is heavily paging and not swapping, the issue could be related to either CPU or memory.
How to do it...
We could use the vmstat and sar command with the following to monitor the paging...
