"Last time we introduced a few common Linux filesystems and
examined their features. If you've already installed Linux, your
partitions are already set up and configured with particular
filesystems, but you may decide you want to modify this
configuration. What's the best way to begin?
"Some changes are tedious to implement. For instance, changing
from one filesystem to another requires you to back up, create a
new filesystem, and restore your files. One exception to this rule
is changing from ext2fs to ext3fs. If you switch filesystems, you
may be able to use filesystem-creation options to improve the
performance of the new filesystem. Other changes can also be done
relatively painlessly. These include defragmenting a disk (that is,
repositioning file contents so that they're not spread out over the
entire partition) and resizing partitions to give you space where
you need it..."