Choosing a Linux Filesystems

With the purchase of a new hard drive comes the exciting activity of partitioning it for use, and with that, choosing the filesystem to use.

In the past, I have always used ext3 for my root partition, and played around with xfs and reiserfs for the other ones. Here is my subjective opinion:

• Ext3 has always been rock-solid, easy to recover (even after creating a reiserfs filesystem *on top* of it), and has good backwards-compatability.
• XFS was used on my DV editing partition, and had very good performance; it was designed with multimedia work in mind. My only complaint is that you can't shrink an XFS filesystem, and since I use LVM, that is annoying.
• ReiserFS has been really fast when deleting many small files. However, I've had a reiserfs filesystem become corrupted *twice*, and I had no luck recovering the data. It probably has to do with the fact that ReiserFS does only metadata rather than full data journaling (see below).

So now I decided to do some research before formating the new drive. Here are some useful sites I found:

• http://linuxgazette.com/issue55/florido.html - A very good technical comparison in the Linux Gazette
• http://freshmeat.net/articles/view/212/ - A less technical overview of the different modern filesystems
• http://linux.org.mt/article/filesystems - General introduction to filesystems on Linux

So what did I come up with? The two most interesting ones appear to be Reiser4 and XFS. I've had my eye on Reiser4 for a long time. It has a very radical design - something that's very interesting from a CS point of view. Visit the NAMESYS website to read all about it. Some benchmarks claim it is the fastest filesystem currently available. Namesys now has patches available for the latest non-mm kernels, so I will definitely try this one out, but I am not going to use it for important data.

XFS has most of the new advanced features described in the Linux Gazette article, but with the added bonus of almost 10 years of good track record. I think I will be using it for most of my files, but ext3 is still my filesystem of choice for my root partition.

I hope this will help someone who needs to make a similar decision. Choosing a filesystem is like choosing a major - you have to do a lot of extra work to change it. Thus choose wisely. I would also very strongly recommend using LVM, even if you have only one disk; it eliminates some of this extra work if you ever have to switch a filesystem.