JFS (Journaled File System) is a file system from IBM. I have always really liked this file system since I first came across it, working with AIX, but I have never used it in a Linux environment until now. When you read comparisons of different file systems it seems JFS always comes out in a top position. For Linux it is sometimes beaten by XFS, but I think that is due to the fact that XFS is more widely used on Linux.

For some reason RedHat seems to have taken out support for JFS in RHES, but it is available for CentOS using the kernel in the CentosPlus repository. The process to upgrade an existing Centos installation to support JFS is simply to update the kernel with the kernel in centosplus and install jfsutils:

yum –enablerepo=centosplus install kernel-smp
yum –enablerepo=centosplus install kernel-smp-devel
yum install jfsutils

Then you probably need to change the “default” row in grub.conf and reboot to start using the new kernel with JFS support.

To create a JFS file system on a new partition use fdisk and mkfs -t jfs.

I think you need to stick to ext3 for the root and boot file systems though and there is no path (at least that I know of) for migrating an existing ext3 file system to JFS “in place”.