在 FreeBSD 及 Ubuntu 啟動 MLS SSD 支援 TRIM

目前手邊的機器每一台都至少裝了一顆 MLC SSD. 不論是當系統碟或當暫存區使用, 都有需要啟動 TRIM. 剛好 FreeBSD 8.2 及 Ubuntu 11.10 的 kernel 都有支援 TRIM. 所以就參考文件設定.

[[[ 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. 參考這篇做測試. HOWTO: Check If TRIM On Ext4 Is Enabled And Working On Ubuntu And Other Distributions


參考資料 Reference:
TRIM support on UFS2 FreeBSD 9
Racklin's 阿土伯程式大觀園: 為 Thinkpad T61 Debian Linux 換上 SSD
HOWTO: Configure Ext4 to Enable TRIM Support for SSDs on Ubuntu and Other Distributions
HOWTO: Check If TRIM On Ext4 Is Enabled And Working On Ubuntu And Other Distributions
How to Tweak Your SSD in Ubuntu for Better Performance