The I/O scheduler in Linux doesn't favour SSD disks so this little trick should keep a more fluent feeling on the desktop.
This hack can be utilized as either a grub setting or through a rc.local script.
Pre Grub 2:
To set the scheduler in grub append this to the kernel parameters. Find the line looking like this:
linux /vmlinuz-2.6.31-14-generic root=/dev/mapper/myhostname-root ro quiet splash
and append this:
linux /vmlinuz-2.6.31-14-generic root=/dev/mapper/myhostname-root ro quiet splash elevator=deadline
Edit the file /etc/default/grub and find this line:
change it to this:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash elevator=deadline"
# update-grub Generating grub.cfg ... Found linux image: /boot/vmlinuz-2.6.31-14-generic Found initrd image: /boot/initrd.img-2.6.31-14-generic Found memtest86+ image: /memtest86+.bin Done
You can also make the changes in the rc.local script:
#!/bin/sh -e # # rc.local # # This script is executed at the end of each multiuser runlevel. # Make sure that the script will "exit 0" on success or any other # value on error. # # In order to enable or disable this script just change the execution # bits. # # By default this script does nothing. echo deadline > /sys/block/sda/queue/scheduler echo deadline > /sys/block/sdb/queue/scheduler echo deadline > /sys/block/sdc/queue/scheduler echo 1 > /sys/block/sda/queue/iosched/fifo_batch echo 1 > /sys/block/sdb/queue/iosched/fifo_batch echo 1 > /sys/block/sdc/queue/iosched/fifo_batch exit 0
The scheduler is per disk, that's why there is a statement per device (/dev/sdX).