What are the differences between ext2 and ext3? Is one faster, more reliable, and/or more efficient?

ext3 is a journaling file system, but is otherwise identical to ext2. Performance wise I think the two are close to identical. For crash recovery though ext3 is much faster.

There's not much difference, really. ext3 is ext2, but with journalling. What this means is that whereas if you had a crash (and hence the filesystem is not unmounted cleanly) and you're using ext2, then you can expect a (often) lengthy fsck (like scandisk) when you reboot. If you're using ext3, then you're given the option of doing an fsck, or you can just let it go and it'll use the journal (last known good state of the filesystem) to 'repair' the filesystem, and thus save time.

There are many other journalled filesystems, such as reiserfs and xfs, jfs, etc, but I prefer to use ext3 because of its backwards compatibility with ext2... therefore if you need to use a rescue disk that doesn't support ext3, you can still access the system because ext3 is extactly like ext2!

Thanks a bunch... well answered.