Re: Best filesystem for loop-aes

Hi David,

I think you've misread the readme slightly. It states


        2.2. Use of journaling file systems on loop device
        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        Don't use a journaling file system on top of file backed loop device. Device
        backed loop device can be used with journaling file systems as device backed
        loops guarantee that writes reach disk platters in order required by
        journaling file system (write caching must be disabled on the disk drive, of
        course). With file backed loop devices, correct write ordering may extend
        only to page cache (which resides in RAM) of underlying file system. VM can
        write such pages to disk in any order it wishes, and thus break write order
        expectation of journaling file system.


So, feel free to use ext3 on a block-device backed loop device as this
guarantees the order of writes which is essential for journal-based
filesystems.

i.e.
OK: ext3 --> loop device -> block device
BAD: ext3 --> loop device -> file

Cheers,
Daniel.
-- 
Daniel Harvey <[email protected]>

On Tue, 2008-02-12 at 21:11 -0800, David wrote:

> Hi everyone;
> 
> Been looking on google but can't find a good answer/explanation;
> What is a "good"/"the best" file system for loop-aes?  The readme states 
> don't use a journaling system (ie ext3), but ext2 is a pain to do a hard 
> restart from because of the fsck time.
> 
> What modern linux file system works well w/loop-aes and has the 
> convenience of quick recovery and stability?
> 
> David
> 
> -
> Linux-crypto:  cryptography in and on the Linux system
> Archive:       http://mail.nl.linux.org/linux-crypto/
>