Linux is a particularly good example to start with for discussing filesystem implementation trade-offs, because it provides all of the common options among its many available filesystems.
Linux filesystems
ext2
The oldest Linux filesystem still viable for use now, ext2, does not have any journaling available. Therefore, any system that uses it is vulnerable to long recovery times after a crash, which makes it unsuitable for many purposes. You should not put a database volume on ext2. While that might work theoretically, there are many known situations, such as any user error made during the quite complicated fsck process, which can break the write ordering guarantees expected by the database.
Rather than presuming that you...
