Not able to mount ext4 file-system in Debian Lenny

Question

I am trying to mount ext4 EBS volume in to my EC2 instance in Debian OS, whenever I try to mount I get the following error:

mount: unknown filesystem type 'ext4'

I googled around and found a link to the solution: http://techtitbits.com/2010/05/mounting-ext4-partitions-on-debian/

No luck, now I get this problem:

mount: unknown filesystem type 'ext4dev'

Not sure what is the exact problem in mounting ext4 file-system. Please help.

Thanks for your time.

NOTE

My kernel version is: 2.6.21.7-2.ec2.v1.2.fc8xen

Debian OS is Lenny 5.0

**ANSWER**

PLEASE DO NOT MOUNT Ext4 filesystem on kernel version < 2.6.28, it will not work, 
since Ext4 was introduced only in >= 2.6.28 kernel version. 

Please see: http://wiki.debian.org/Ext4

Solution 1

PLEASE DO NOT MOUNT Ext4 filesystem on kernel version < 2.6.28, it will not work, since Ext4 was introduced only in >= 2.6.28 kernel version.

Please see: http://wiki.debian.org/Ext4

Solution 2

Don't do it. The experimental ext4 module that was included in Lenny isn't safe or sane to use on a disk that you actually want to store data on.

Still, the mount operation should work alright once the test_fs flag is set. What's the exact output from these commands, filled in with the relevant info for your system?

tune2fs -E test_fs /dev/sdXX
mount -t ext4dev -o ro /dev/sdXX /mnt/mountpoint

Comments

[Greg Petersen]

lsmod | grep ext4 or grep -i ext4 /path/to/the/kernel/.config?

[Rakesh Sankar]

lsmod shows nothing, whereas with kernel/.config - I am not sure I know the path to kernel folder, can you help me with that?

[Greg Petersen]

Take a look at /usr/src/linux....

[Rakesh Sankar]

Thanks for the answer @Shane-madden, it looks like Ext4 is introduced in Linux Kernel version > 2.6.28 (from this link), where as my version is 2.6.21 :-( - that said I will have to upgrade my kernel version and give it a try.