Sar -r (memory)

sar -r --human

09:38:01 PM kbmemfree   kbavail kbmemused  %memused kbbuffers  kbcached  kbcommit   %commit  kbactive   kbinact   kbdirty
09:39:01 PM    122.1G    478.5G    381.5G     75.8%    385.4M    348.8G     25.4G      5.0%     39.7G    330.0G     96.2M
09:40:01 PM    118.7G    478.5G    384.9G     76.4%    385.5M    352.1G     25.4G      5.0%     39.8G    333.2G    406.1M
09:41:01 PM    116.1G    478.4G    387.4G     76.9%    385.6M    354.6G     25.4G      5.0%     39.9G    335.7G    259.2M

00:00:01    kbmemfree   kbavail kbmemused  %memused kbbuffers  kbcached  kbcommit   %commit  kbactive   kbinact   kbdirty
00:05:01       131.5M    305.9M    853.7M     86.7%     48.8M    292.3M      1.5G    157.4%    567.6M    175.3M    632.0k
00:10:01       128.7M    303.4M    856.5M     86.9%     48.9M    292.4M      1.5G    157.1%    570.2M    175.4M    300.0k
00:15:01       130.0M    304.9M    855.2M     86.8%     49.1M    292.4M      1.5G    157.1%    568.9M    175.3M    288.0k
00:20:01       129.7M    305.0M    855.5M     86.8%     49.3M    292.6M      1.5G    157.5%    569.0M    175.5M    328.0k

Activities

1. Review total system memory: free -h
2. Emptying the buffers cache: free -h && sync && echo 3 > /proc/sys/vm/drop_caches && free -h
3. Use fio with direct=0 to fill up your cache.

Related commands

• swap: sar -S

See also

• Swap, swapon, swapoff, mkswap, swaplabel, free,sar -r, sar -S, sar -W, vmstat, vm.swappiness, /proc/swaps, /etc/fstab, Add a swap disk, systemd.swap
• systemd-cgtop
• Memory: RAM, DRAM, SDRAM, NVRAM, DMA, ECC, VRAM, Nanya, SGRAM, DDR

https://unix.stackexchange.com/questions/87908/how-do-you-empty-the-buffers-and-cache-on-a-linux-system