Is this still a valid recommendation?
Paul
yes. why do you want to use ext4? iow, what advantage do you think you will get? if you do not have a good answer then stay away. stick with ext3.
this is not an area where you should be experimenting. for database storage, you need reliability and stability.
note that /most/ filesystem differences do not have much impact on performance of the types of I/O that databases perform. there are of course exceptions, ZFS being one that comes to mind.
this is an ultra conservative answer for those people who are risk averse with their data.
if you want to give it a try, read up on it first, then make sure your stuff is properly backed up
see here: www.thegeekstuff.com/.../ext2-ext3-ext4
note that ext4 has been around long enough that it should be quite stable now but i have note looked at the bug reports for it recently so i can't be sure.
one of the advantages of ext4 is that performance of space allocation when expanding a file should be better than ext3.