Which filesystem for 16TB under CentOS 5.5?

Solution 1:

Definitely XFS. XFS initialisation is much faster, performance is excellent, and XFS has been use for multi-terabytes volumes for ages. I currently support 230 machines with 8 to 76 TB XFS volumes. Tens are built with two or more RAID volumes aggregated through LVM without problem, so this is safe enough.

xfs_check speed depends mostly on the number of files. For typical large volumes (30 TB), xfs_repair takes less than 15 minutes given that the system has enough memory (older xfs_repair tends to gobbles tons of RAM), like 8 GB or more.

Solution 2:

We have backup servers including 8-12TB of space, first one (10TB) running ext3 without any problems, and others running ext4.

ext4 seems to be much faster with large partitions and huge number of files. We use only single very large partition for data, as it is so much more flexible. And of course separate partition for root filesystem. We are using hardware RAID5 and LVM.

As of minimizing time for fsck, first advice would be shutting down server in right way whenever possible.

If you can easily split your filesystem in reasonable way to multiple smaller partitions, I would go with LVM and your filesystem of choice (ext3 is mature, and so is XFS. Many people are using ext4 without any problems). If you have smaller partitions, fsck will be faster, assuming that you don't have to fsck all partitions every time.

Of course you can also run fsck only on mandatory partitions at first (to get most important things up and running) and then continue running fsck on other partitions before mounting those.