The latest benchmarks of filesystem performance at Phoronix seem appealing. Using the Jaunty development version and the latest Linux 2.6.28 kernel, I was able to upgrade my filesystem from EXT3 to EXT4. So far, I haven’t really noticed anything vastly different, but it’s only been a short time with this new filesystem. Here’s wishing you a painless transition like mine.
Supposedly it’s best to refrain from doing this to your /boot filesystem
First, figure out what partition you want to change. You may first list the partitions to see what the device name is.
sudo fdisk -l
Look for the /dev/sd@# of your Linux partition where @ is a letter and # is a number. For example, mine was /dev/sda6. Once we know this, just run a few commands.
tune2fs -O extents,uninit_bg,dir_index /dev/sd@#
fsck -pf /dev/sd@#
Then we need to edit /etc/fstab so that it mounts as ext4 when we boot.
gksudo gedit /etc/fstab
Find the device that you converted to ext4 and change the ext3 reference to ext4. Save. Reboot. Enjoy ext4.
Note to self: file bug report in launchpad since gparted doesn’t recognize my ext4
Posts
If you want to use ext4 at its full capability, you can not simply upgrade.
You have to backup your data, reformat your disk new in ext4, and then restore your data.
January 15, 2009 @ 5:22 am
What do you mean by “full capability”? What am I missing out on by this “upgrade” process?
January 15, 2009 @ 8:30 am
When upgrading from ext3 to ext4 only newly created files are written with extents. Files already existing on the partition do not get converted in the new format.
January 17, 2009 @ 1:20 pm
There’s another thing that must be mentioned. All your existing files will continue using the old indirect mapping to map all the blocks of data. The online defrag tool will be able to migrate each one of those files to a extent format (using a ioctl that tells the filesystem to rewrite the file with the extent format; you can use it safely while you’re using the filesystem normally)
January 20, 2009 @ 3:00 pm