Arch Linux

cb474

Member

Registered: 2009-04-04

Posts: 469

loopback filesystem with ext4 (instead of ext2) okay?

In the wiki, the section that describes how to create an encrypted loopback filesystem, directs you to use the ext2 filesystem:

https://wiki.archlinux.org/index.php/Sy … filesystem

Is there any reason not to use ext3 or ext4? Or was that part of the wiki just written a long time ago?

Thanks.

Russano

Member

Registered: 2011-03-18

Posts: 2

Re: loopback filesystem with ext4 (instead of ext2) okay?

The filesystem you use to format the loopback device should not matter. Once you have used losetup to create the loopback device, /dev/loopX behaves like any other block device. You can format it the same way that you would format a USB thumb drive. And you are not limited to ext2/3/4 but can use almost any filesystem format.

I'm pretty sure that ext2 was used in the wiki article because it is a stable filesystem, and because it is not journalled. The example in the wiki only creates a 10MB loopback device, and the ext4 journalling would consume about 1MB of that available space where the overhead with ext2 is only about 100k.

You should have no trouble with using ext4, or any of the other supported filesystems. The only real limit to what you can use to format and mount the loopback device are which kernel modules and filesystem utilities you have installed.

cb474

Member

Registered: 2009-04-04

Posts: 469

Re: loopback filesystem with ext4 (instead of ext2) okay?

Thanks for the explanation!