Our new backup software which I was configuring earlier this week recommends using Ext4 as it’s filesystem, at first I thought it would be OK to run on Ext3 as this is what the server had already set-up, but then I found out that it was a simple few commands to upgrade partitions from Ext3 to Ext4 – here’s what I ran:

To convert a partition from Ext3 to Ext4 on CentOS 5.6.

If ef4sck isn’t installed:
* yum install e4fsprogs

Once installed you can then use the following commands to upgrade the filesystem.

* umount /Partition_Name
* tune4fs -O extents,uninit_bg,dir_index /dev/Volume_Name/Partition_Name
* e4fsck -fDC0 /dev/Volume_Name/Partition_Name

Now edit the /etc/fstab file to update the filesystem the partition uses from ext3 to ext4 and you can mount the drive again.

* mount /Partition_Name

We would always recommend running this on a test system first and not on your live systems, unless full backups have been taken first and downtime will be non-critical, in case of any issues.