ext4 testing in the F10 release cycle

[Eric Sandeen]

Sven Lankes wrote:
> On Wed, Sep 03, 2008 at 11:19:04AM -0500, Eric Sandeen wrote:
> 
>> With the e2fsprogs-1.41.0 release in F10, we now have an ext4-capable
>> e2fsprogs, with working fsck, debugfs, etc as well as mkfs.ext4 and
>> mkfs.ext4dev to enable the new disk format features by default.
> 
> Is converting ext3 to ext4 also a supported use case in fedora-land?

Anaconda doesn't yet handle the migration FWIW...

> According to the ext4-wiki 
> 
>   tune2fs -O extents -E test_fs /dev/DEV

That will let you mount it as ext4dev, yes. It doesn't enable all the
on-disk format stuff; uninit_bg and flex_bg can also be tune2fs'd on,
although honestly I think this could use more testing for corner cases.

> (and then remounting as ext4dev) should work.
> 
> Also is there (going to be) any sort of online defragmentation support
> to make a converted ext4 use extends for all files?

There is talk of that, but defrag support is not yet available.  The
patches are in the pending queue but not getting a lot of attention ATM.

There have been other options discussed, such as transparently
re-writing at least small files in extents format (though this wouldn't
improve existing allocation).

-Eric