Reduce Flash Writes
From PlugWiki
The following are suggestions to reduce the number of writes to the Flash file system and extend the life of the Plug Flash memory
Contents |
Reduce Swapping
To see the current setting
#cat /proc/sys/vm/swappiness
To set:
# echo 0 >/proc/sys/vm/swappiness
To make the change permanent add the following line to /etc/sysctl.conf
vm.swappiness=0
Enable Laptop Mode
Laptop mode works by submitting all future pending disk IO at once.
To see if laptop mode is enabled run
# cat /proc/sys/vm/laptop_mode
Use this command to enable laptop mode
# echo 5 > /proc/sys/vm/laptop_mode
To make the change permanent add the following line to /etc/sysctl.conf
vm.laptop_mode=5
Reduce Cache Writeback TIme
You can check the current value of this writeback time with these commands:
# cat /proc/sys/vm/dirty_writeback_centisecs # cat /proc/sys/vm/dirty_expire_centisecs
Increase the time to 15 seconds with the following commands:
echo 1500 > /proc/sys/vm/dirty_writeback_centisecs echo 1500 > /proc/sys/vm/dirty_expire_centisecs
To make the change permanent add the following line to /etc/sysctl.conf
vm.dirty_writeback_centisecs=1500 vm.dirty_expire_centisecs=1500
Filesystem relatime
relatime works by updating the atime field on disk only if the file hasn't been accessed since the last time it was accessed
A discussion of the relatime option can be found at http://lwn.net/Articles/244829/.
Change /etc/fstab to
rootfs / rootfs relatime,rw 0 0
Reduce syslog file syncing
syslogd will in the default installation sync a lot of log files to disk directly after logging some new information. You might want to change /etc/syslog.conf so that every filename starts with a - (minus) which means that writes are not synced immediately (which increases the risk that some log messages are lost if your system crashes). For example, a line such as:
kern.* /var/log/kern.log
would be changed to
kern.* -/var/log/kern.log
On Debian, you may be using rsyslog, in which case, add the following to /etc/rsyslog.conf
$ActionFileEnableSync on
