SSD在Ubuntu下的优化
Category: /knowledge /linuxTags: linux
system
in /etc/fstab
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc nodev,noexec,nosuid 0 0
tmpfs /tmp tmpfs defaults,noatime,nodiratime,mode=1777 0 0
none /var/log aufs br:/tmp=rw:/var/log=ro 0 0
# / was on /dev/sda1 during installation
UUID=50143bce-e400-418b-a8d4-c8e596820fb3 / ext4 noatime,nodiratime,data=writeback,barrier=0,nobh,commit=25,errors=remount-ro 0 1
in /etc/default/grub,
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash elevator=deadline rootflags=data=writeback"
to write that to disk, changed the ext4 file system to use the data=writeback journal mode:
tune2fs -o journal_data_writeback /dev/sda1
/etc/rc.local
echo 1 > /sys/block/sda/queue/iosched/fifo_batch
for dir in apparmor apt news cups dist-upgrade fsck gdm installer samba unattended-upgrades
do
if [ ! -e /var/log/$dir ]
then
mkdir /var/log/$dir
fi
done
if [ -d '/sys/module/hid_apple' ] ; then
echo 2 > /sys/module/hid_apple/parameters/fnmode
elif [ -d '/sys/module/hid/parameters' ] ; then
echo 2 > /sys/module/hid/parameters/pb_fnmode
fi
/etc/sysctl.conf
vm.dirty_ratio = 40
vm.dirty_background_ratio = 1
vm.dirty_writeback_centisecs = 24000
vm.swappiness = 1
To use tmpfs for /var/lock and /var/run, you can simply symlink them to /run. Make sure to close anything important before doing this, because you will have to reboot, and daemons may not stop cleanly.
ln -sf /run/lock /var/lock
ln -sf /run /var/run
Application
Firefox ———-
* Open Firefox.
* Type about:config in the search bar.
* Right click on any row.
* Select New > String from the popup menu.
* Add browser.cache.disk.parent_directory and set it to /tmp
* set Edit/Preferences/Downloads directory to /tmp
* Restart Firefox.
Use about:cache to verify.
Google Chrome
Chrome 在Linux下cache的位置是~/.cache/google-chrome/Cache. 只要把这个目录链接到内存里就可以了.
cd ~/.cache/google-chrome/Default
rm -rf Cache
ln -s /tmp Cache
rm -rf Media\ Cache
ln -s /tmp Media\ Cache
Or make the entire cache folder to /tmp
cd
rm -rf .cache
ln -s /tmp .cache
NX client
edit rc.local
vim
do sth about .viminfo
ln -sf /tmp/.viminfo .
User data
sudo chown root:root .Xauthority .xine .xsession-errors
sudo chattr +i .xsession-errors
ln -sf /tmp/bash_history .bash_history
or disable .bash_history, in ~/.bashrc
unset HISTSIZE
Compare with HDD
AMD dual core, 2.0 GHz, My regular 7200rpm HDD:
sudo hdparm -tT /dev/sda5
/dev/sda5:
Timing cached reads: 1184 MB in 2.00 seconds = 591.93 MB/sec
Timing buffered disk reads: 218 MB in 3.02 seconds = 72.27 MB/sec
C2D 2.66 GHz, OCZ Vertex 30GB SSD:
sudo hdparm -tT /dev/sda
/dev/sda:
Timing cached reads: 12380 MB in 1.99 seconds = 6213.86 MB/sec
Timing buffered disk reads: 552 MB in 3.00 seconds = 183.77 MB/sec
虽然没达到传说中的220MB/sec, 结果还是相当满意的.
Kingston V 64GB SSD
sudo hdparm -tT /dev/sda2
/dev/sda2:
Timing cached reads: 13242 MB in 1.99 seconds = 6646.65 MB/sec
Timing buffered disk reads: 748 MB in 3.01 seconds = 248.91 MB/sec
Test writing speed
dd if=/dev/zero of=/tmp/output.img bs=8k count=128k
