Linux / Unix Tips and Tricks

fsck: Filesystem has unsupported features

len | 12 December, 2008 10:49

Last month I have migrated several physical Linux servers to VMWare using this excellent howto: Virtualize a Server with Minimal Downtime

After migrating an old RedHat 9 server to VMWare, I got an error saying fsck.ext3: Filesystem has unsupported features.
This is because RedHat 9 does not understand the new file system features created with the Knoppix boot CD. Luckily, the unsupported file system features can be easily removed. Here is how I did it:

First compare the file system features of the old and the new server by issuing the following command on both systems:

tune2fs -l /dev/sda1 | grep features

In my case the virtualized server had two extra features: dir_index and resize_inode
To remove the extra features you can either use tune2fs or the debugfs command:

On the virtualized server:

tune2fs -O "^dir_index,^resize_inode" /dev/sda1

Or alternatively you can use:

debugfs -w -R "features ^resize_inode ^dir_index" /dev/sda1
After changing the filesystem features you need to run a filesystem check:

fsck -y /dev/sda1

Repeat the steps above for the other filesystems you might have.