vmstat has default output which is similar in nature and takes many options that give extremely detailed information, eg vmstat -m swapinfo would cover the swap part top -d1 causes top to print one screen and exit, and the banner is very similar to free. Use top -d1 | head -n 7 to see only … Read more
Modern operating systems go out of their way to keep as little memory free as possible. Memory that is free is actually harder to use because it has to be transitioned from free to in use. Memory that is already in use, that is, memory that is available but not free, can easily be switched … Read more
Don’t look at the “Mem” line, look at the one below it. The Linux kernel consumes as much memory as it can to provide the I/O cache (and other non-critical buffers, but the cache is going to be most of this usage). This memory is relinquished to processes when they request it. The “-/+ buffers/cache” … Read more