目前手边的机器每一台都至少装了一颗 MLC SSD. 不论是当系统碟或当暂存区使用, 都有需要启动 TRIM. 刚好 FreeBSD 8.2 及 Ubuntu 11.10 的 kernel 都有支援 TRIM. 所以就参考文件设定.
[[[ FreeBSD 8.2 ]]]
1. Reboot and login in Single User Mode
2. tunefs -p /dev/adXXsXX
3. tunefs -t enable /dev/adXXsXX
4. Reboot the machine
5. Check the setting
HHHHH(XXXXXX)/root# tunefs -p /dev/adXsXX
tunefs: POSIX.1e ACLs: (-a) disabled
tunefs: NFSv4 ACLs: (-N) disabled
tunefs: MAC multilabel: (-l) disabled
tunefs: soft updates: (-n) disabled
tunefs: gjournal: (-J) disabled
tunefs: trim: (-t) enabled
tunefs: maximum blocks per file in a cylinder group: (-e) 2048
tunefs: average file size: (-f) 16384
tunefs: average number of files in a directory: (-s) 64
tunefs: minimum percentage of free space: (-m) 8%
tunefs: optimization preference: (-o) time
tunefs: volume label: (-L)
[[[ Ubuntu 11.10 ]]]
1. Edit /etc/fstab and add “discard,noatime,nodiratime,”.
root@HOSTNAME:~# diff /etc/fstab.bak /etc/fstab
10c10
< UUID=dXXXdXXX-5899-XXXX-XXXd-XXXXcXXX8XXX / ext4 errors=remount-ro 0 1
—
> UUID=dXXXdXXX-5899-XXXX-XXXd-XXXXcXXX8XXX / ext4 discard,noatime,nodiratime,errors=remount-ro 0 1
2. Edit /etc/rc.local and add following statements before ‘exit 0’.
### For tweak SSD
echo noop > /sys/block/sda/queue/scheduler
echo 1 > /sys/block/sda/queue/iosched/fifo_batch
3. Reboot the machine
4. 参考这篇做测试. https://sites.google.com/site/lightrush/random-1/checkiftrimonext4isenabledandworking