Administrators familiar with the Linux /proc filesystem will know that it is a valuable source for both device status and performance information. The meminfo entry in this directory will always provide copious data regarding the status, contents, and state of the memory in our server.
We care about this as DBAs because file cache and write buffering can drastically affect disk I/O. We are not especially interested in analyzing PostgreSQL's memory usage itself at this point, except in the context of client connections, inode caches, and dirty page flushing.
On a modern Linux kernel, there are over 50 different lines of information in /proc/meminfo. Much of this data is not exceptionally useful to a DBA, so this recipe will focus on important fields only.
