If your installing CentOS 5 and you need the XFS filesystem then you need to install a special kernel module from the extras repository. If your going to use XFS filesystem you should also install the XFS programs that go with it. There is an easy way to see what XFS kernel modules are available for your kernel. Make sure the extras repo is turned on in /etc/yum.repos.d/CentOS-Base.repo. Then try the following command to list the XFS packages available for your running kernel:
yum list available kmod-xfs\*
Then pick the kernel module based on the kernel your running (uname -a). If your running an smp kernel then you would choose kmod-xfs-smp.i686 for i686 class processor. For example to install the smp XFS module and the xfs programs try the following:
yum install kmod-xfs-smp.i686 xfsdump xfsprogs
I've been testing filesystem speeds on new hardware SATA RAID cards and have some suggestions. If your working with lots of medium to large size data files then SGI's XFS is a great way to go. It is super fast but there are a few drawbacks as with all filesystems. It takes up more processing time while it's working and can only do a few hundred deletes a sec. Now if you have a hardware raid card that does on chip parity calculations (like the Areca line of RAID cards) then you should have plenty of processor to devote to the system. That is if you don't need it for something else. XFS had the fastest throughput without a doubt. ReiserFS 3 was decent but it did not handle larger files as well as XFS and it's throughput was not as high. ReiserFS is fantastic with smaller files (up to a few megs) and it rocks in delete speed. It would be great for a home user filesystem. EXT3 was the worst. It was slowest by big margin in everyway. I would only use it on a home users machine. It is not built for speed but for reliability. Future improvements and more tweaks might help the tests but with just some default settings this is how it panned out.
I also learned that XFS's block size can not go above the page size of the running kernel. In linux this is 4k.
The settings I found to help speed up the XFS filesystem are the following. Partition the drive first. /dev/sda1 is the device and partition in the example below.
mkfs.xfs -f -b size=4k -l size=64m /dev/sda1
mount -t xfs -o logbufs=8 /dev/sda1 /disk1