Ext4 FAQ

[Will Woods]

On Tue, 2009-04-28 at 11:50 -0430, Patrick O'Callaghan wrote:
> On Tue, 2009-04-28 at 21:26 +0530, Rahul Sundaram wrote:
> > Hi
> > 
> > I have put up a FAQ at
> > 
> > https://fedoraproject.org/wiki/Ext4_in_Fedora_11
> > 
> > I will be expanding this over time. If you have other unanswered
> > questions, do let me know.
> 
> OK, here's one. The FAQ says "You can use the Anaconda boot option,
> "ext4migrate" to automatically migrate from Ext3 to the new Ext4
> filesytem when upgrading from a previous release of Fedora".
> 
> What does this mean in practice? Is the end result equivalent to backing
> up my ext3 partition and restoring under ext4, or does it simply mount
> the ext3 partition as ext4?

It mounts as ext4 *and* enables the 'extents' feature. So the files
written during the upgrade should be using extents - but not everything
on the system gets rewritten. /home, for instance, will be essentially
untouched.

So.. it's a little fancier than just mounting as ext4, but less invasive
and time-consuming than doing a full backup/restore.

-w