I have an Marwell Kirkwood ARM-based NAS server Zyxel NSA 310. I compiled my own 3.8 kernel and enabled ZCACHE, but I still see 256 MB of RAM. I am not sure if GNU free utility should show extra amount of RAM. How do I find out it is really working? Do I need to do some extra steps to make use of it? I have added "zcache" to the command line.
root@nas:~# free -m
total used free shared buffers cached
Mem: 247 218 29 0 7 166
-/+ buffers/cache: 43 203
Swap: 1427 0 1427
root@nas:~# zgrep CACHE /proc/config.gz
CONFIG_CLEANCACHE=y
CONFIG_ZCACHE=y
root@nas:~# dmesg | grep zcache
Kernel command line: console=ttyS0,115200 root=/dev/sda3 zcache
zcache: using lzo compressor
zcache: cleancache enabled using kernel transcendent memory and compression buddies
zcache: cleancache: ignorenonactive = 1
zcache: frontswap enabled using kernel transcendent memory and compression buddies
zcache: frontswap: excl gets = 1 active only = 1
zcache: created ephemeral local tmem pool, id=0
zcache: created persistent local tmem pool, id=1
zcache: created ephemeral local tmem pool, id=2
zcache: created ephemeral local tmem pool, id=3
zcache: created ephemeral local tmem pool, id=4
root@nas:~# cat /proc/cmdline
console=ttyS0,115200 root=/dev/sda3 zcache
I know it is "merging" pages compressing them, but how to see the compression ratio or something like that.
