Linux – Which file systems do support file locking

Its performance doesn't scale well with multiple processing cores due to the specific implementation.

Prior versions were actually fairly prone to corruption (and I've encountered this multiple times), though that's supposedly resolved in current versions.

Its fsck can actually end up causing more corruption on an already heavily corrupted filesystem.

Upgrading to its successor, Reiser4, requires a complete backup and restore, since it's effectively a completely different filesystem, unlike ext2->ext3->ext4.

There are very few developers actually working on Reiserfs, which means that if and when problems occur, there's not much support to fix them.

Much of this information is from one of the head SuSE developers when they decided to switch their default filesystem from Reiserfs to ext3.

i am unaware of any way to non-destructively convert a file system. this does not mean it is impossible, but i would put it at very low odds.

you can, for example, convert from ext2 to ext3 without wiping the disk, and from ext3 to ext4.

but to go from something like jfs to ext4 seems highly improbable, without first copying your /home files to another partition or external hard disk.

even then, you would want to create a new user on your system, with a home directory somewhere like /tmp/tempuser or copy your configurations for your user, usually the 'dot' files (files beginning with .) in your home directory to a new location off /home and updating /etc/passwd to use the new home directory, so you can log in as a normal user while you're performing this update.

then, back up your files, unmount /home and format it using /sbin/mkfs.ext4 or whatever tool you plan to use. mount the fresh partition at /home and copy your files back.

also, i would recommend something 'intelligent' like rsync to copy your files, to assure you preserve your permissions and all that jazz.