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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 <daniel@xxxxxxxxxxxxxxx>

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

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