Previously I recommended not to install using ext4 because there is a kernel process that is calling constantly and needing to check the disk if you do and will be one of many many processes that will screw up your power management. This issue seems to be fixed in the recommended kernel I list below. You can still read about the issue people were having on the ArchLinux Forums, home to tons of good information for eeepc owners. In particular, user lagagnon explains the issue as follows:
lagagnon wrote:
More info: using "iotop" the culprit appears to be "jbd2/sda1-8", which appears to be a kernel process associated with journaling on the ext4 filesystem, if my googling around is correct. And yes it is an Atom processor here also. Strange, guess will just have to wait and see if future updates fixes it. Does not seem correct that it has to access the disc so often.
Just for fun it appears this issue did not get seem to be fixable by noatime so simply disabling journaling was not a fix. The only fix appeared to be in not using ext4. So we had to ask ourselves whether the speed in boot times is worth the random processor overruns, the overheating that seems to result, and the inability to use many commercial backup imaging programs? Thankfully this no longer seems to be an issue and the trade offs are no longer necessary if you use the kernel recommended further down below.
Still, there are some situations where ext3 is better in Lucid than ext4, so you'll have to do some homework. I do not recommend reiserfs, because you will find yourself doing disk checks nearly every other day and it is an unsupported filesystem with a very limited future.
Update!
User Ceno reports that there is a way to use ext4 and disable journaling thus fixing the jbd2/sda1-8 bug, but it is a bit involved, so your mileage may vary! Personally I intend to stick with the kernel mentioned above and explained below, but for those who might be interested, here is that fixed:
Ceno wrote:
Regarding the jbd2/sda1-8 "bug", if you will, mentioned in the File System section of the 1st post, disabling journaling does indeed solve it.
First thing's first, we can confirm that our ext4 partition is running a journal with
$sudo dumpe2fs /dev/sdaX | grep has_journal
Disabling journaling is rather easy, the only drag is that to make structural changes to a filesystem, the filesystem cannot be mounted with read/write privileges. So, run a live cd and hit
$sudo tune2fs -O ^has_journal /dev/sdaX
And it's done. Now when you boot, the change will be noted and the disk will be checked for errors. When the system is finally up we can run this again to confirm that in fact ext4 is running without a journal
$sudo dumpe2fs /dev/sdaX | grep has_journal
should now return nothing.
With this quick fix, no more constant IO peaks. I can now watch youtube videos without constant freezes.