Ext4 FAQ

[Patrick O'Callaghan]

On Tue, 2009-04-28 at 16:12 -0430, Patrick O'Callaghan wrote:
> On Tue, 2009-04-28 at 14:27 -0400, Will Woods wrote:
> > 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.
> 
> OK, that's clear enough, thanks.

Actually it was a little less clear than I originally thought. I
installed F11 as an upgrade to F10 and wasn't asked if I wanted to
upgrade my filesystems to ext4. Only on revisiting the FAQ did I notice
that I would have had to give the "ext4migrate" option to Anaconda. I
had mistakenly assumed that this would be settable interactively.

In fact I don't quite see why it isn't.

poc