Différences

Ci-dessous, les différences entre deux révisions de la page.

--- tech:disque_cache_flush_sync_io_purge [2025/06/01 15:57] – Jean-Baptiste
+++ tech:disque_cache_flush_sync_io_purge [2026/07/17 10:35] (Version actuelle) – Jean-Baptiste
@@ Ligne 1: / Ligne 1: @@
+<!DOCTYPE markdown>
+{{tag>Brouillon FS Cache}}
+# 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`
+~~~bash
+echo 3 | sudo tee /proc/sys/vm/drop_caches
+~~~
+~~~bash
+#!/bin/bash
+sync
+echo 3 >/proc/sys/vm/drop_caches
+swapoff -a && swapon -a
+~~~
+~~~bash
+# (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
+~~~bash
+watch grep -e Dirty: -e Writeback: /proc/meminfo
+awk '{print $9}' /sys/block/sda/stat
+~~~