Memcached 1.5.18 and later versions of the cache memory can be restored when the service is restarted. The new version also be achieved by caching persistent public function DAX file system is mounted.
You can use this function through the startup options:
-e /tmpfs_mount/memory_file
/ Tmpfs_mount / must be some type of ram disk, large enough to satisfy the memory limit specified in the -m startup.
Realization gracefully restart: send SIGUSR1 signal to the daemon, and wait for it to close and exit. /Tmpfs_mount/memory_file.meta file created when closed.
When you restart, it reads this file and ensure compatibility. If the file is not compatible or file is corrupt, it will start with a new cache.
Here are some more if parameters, the cache will be cleaned:
Memory limit (-m)
maximum project size.
Slab block size plate.
CAS is enabled.
Whether to allow the slab redistribution.