On Sun, Jan 11, 2009 at 3:28 PM, Theodore Tso <[email protected]> wrote:
> On Sun, Jan 11, 2009 at 01:44:43PM +0000, Alex Buell wrote:
>> Can someone confirm if the online ext4 defragmentation ioctls will
>> be going into 2.6.29? Thanks, I'm planning a migration from a
>> disparate collection of filesystems to ext4 over the next few months.
>
> Unfortunately, the defragmentation patches need to a lot of work (to
> be honest, largely refactored and almost rewritten) before they are
> ready to for mainline yes. I am also concerned that the current
> defrag patches also try too hard to keep blocks in the same block
> group, even as a higher priority keeping them non-fragmented.
>
> Also, note that some of the benefits of ext4 only show up if you do a
> backup, mkfs, and restore; that's because there are layout changes
> that can only take place if you reformat the filesystem. Finally,
> there are some allocation algorithm changes which didn't make the
> 2.6.29 merge window which I think will make a long-term difference.
> So you'll probably want to use 2.6.29 with the ext4 patch set.
Hi Ted,
Could you elaborate on which allocation patches you're referring to in
the ext4 patch queue (2.6.28-ext4-3?) ?
Thanks,
Mike
On Mon, Jan 12, 2009 at 08:39:33AM -0500, Mike Snitzer wrote:
>
> Hi Ted,
>
> Could you elaborate on which allocation patches you're referring to in
> the ext4 patch queue (2.6.28-ext4-3?) ?
They haven't been implemented yet. They've been discussed on the ext4
mailing list, however. Basically, the Orlov algorithm was disabled
for flex_bg, and I want to optimize how directory blocks are allocated
to hopefully speed up fsck times a tad bit more. The design has been
roughly worked out; but it's a matter of me finding time to code and
test it...
- Ted
On 1/12/09, Theodore Tso <[email protected]> wrote:
> On Mon, Jan 12, 2009 at 08:39:33AM -0500, Mike Snitzer wrote:
> >
> > Hi Ted,
> >
> > Could you elaborate on which allocation patches you're referring to in
> > the ext4 patch queue (2.6.28-ext4-3?) ?
>
>
> They haven't been implemented yet. They've been discussed on the ext4
> mailing list, however. Basically, the Orlov algorithm was disabled
> for flex_bg, and I want to optimize how directory blocks are allocated
> to hopefully speed up fsck times a tad bit more. The design has been
> roughly worked out; but it's a matter of me finding time to code and
> test it...
Ah, that ext4 thread is here:
http://kerneltrap.org/mailarchive/linux-ext4/2008/12/12/4403324
Thanks for clarifying,
Mike