Gjournal reporting 1/2 the speed of non journaled? What is the status of Gjournal?

[N. Harrington]

--- Pawel Jakub Dawidek <pjd at FreeBSD.org> wrote:

> On Thu, Aug 16, 2007 at 06:02:09PM -0700, N.
> Harrington wrote:
> >  With ZFS, I have not seen much new going on with
> > gjournal. I am curious what the status of gjournal
> and
> > if it will likely be included with 6.3 (whenever
> that
> > is due)
> 
> That was the plan, but I'm not yet sure if I'll find
> time to do it.

 I hope so. It seems like everything is there.

> >  Also, as of late, I have been using it with
> > 6.2-STABLE via the patches and I seem to be
> getting
> > 1/2 the transfer speeds compared to non journaled
> > disks. It seems like this is recent as previous
> tests
> > showed it as quite fast.
> > 
> >  Any suggestions on why this could be happening
> > greatly appreciated.
> > 
> >  tested via 
> >  dd if=/dev/zero of=./testfile bs=16 count=16384
> 
> Gjournal is ~two times faster than UFS+SU for many
> small, random and
> parallel writes (such as running few 'tar x'
> processes), but is two
> times slower than UFS+SU for one sequential write
> stream, as there is no
> much that can be optimized there.

 Is there a test that I could try? I would swear that
using the same test in the past, it showed as faster. 


> >  With disks getting larger and larger, why is it
> > taking so long for a journaled filesystem to be
> > standard on BSD?
> 
> We have ZFS now, we don't need journaled file
> system:)

 I guess I need to learn now about ZFS. As far as I
know it is not available in 6 yet and it is for raid,
not for journaling or a filesystem itself.

 It would seem silly to have to resort to using zfs
just so I can have a disk/mount that won't not require
days to fsck (9 times out of 10) if there should be a
problem.  gjournaling has been the only thing that has
kept FreeBSD used at my company for file storage. I
have many many active TB's with it. Much of it in 500G
slices, which I was thinking of increasing to 1TB
slices. I could never do that with UFS with any sanity
or hope of having a job after the day long fsck. I
certainly could never justify why we should not switch
to Linux to prevent it otherwise. 

 I am so grateful you did gjournaling. If I thought we
could afford it, we would pay to make sure its
included in 6.3.


 Nicole


> -- 
> Pawel Jakub Dawidek                      
> http://www.wheel.pl
> pjd at FreeBSD.org                          
> http://www.FreeBSD.org
> FreeBSD committer                         Am I Evil?
> Yes, I Am!
>