Disque cache flush sync io purge

Source :

http://stackoverflow.com/questions/9551838/how-to-purge-disk-i-o-caches-on-linux

https://www.kernel.org/doc/Documentation/sysctl/vm.txt

https://en.wikipedia.org/wiki/Sync_(Unix)

drop_caches.sh

echo 3 |sudo tee /proc/sys/vm/drop_caches
#!/bin/bash sync echo 3 >/proc/sys/vm/drop_caches swapoff -a && swapon -a
# (move data, modified through FS -> HDD cache) + flush HDD cache sync # (slab + pagecache) -> HDD (https://www.kernel.org/doc/Documentation/sysctl/vm.txt) echo 3 > /proc/sys/vm/drop_caches blockdev --flushbufs /dev/sda hdparm -F /dev/sda # Command that should be run before unplug, flushes everything guaranteed echo 1 > /sys/block/sdX/device/delete

watch the progress of a sync operation Source : http://unix.stackexchange.com/questions/48235/can-i-watch-the-progress-of-a-sync-operation

watch grep -e Dirty: -e Writeback: /proc/meminfo awk '{print $9}' /sys/block/sda/stat