Peter Samuelson wrote:
> [Dr. Michael Weller <eowmob@exp-math.uni-essen.de>]
> > I mean, what you really want is: have the journal on a separate
> > partition with no filesystem at all. Best of all on a seperate disk
> > (controller, maybe). And you might want to have one journal only for
> > all filesystems.
>
> AIX does this. There is one journal LV (logical volume) for each VG
> (volume group). This (rather than one journal per whole system) is
> because the VG is intended to be the unit of portability,
Thats statement is dependent on if you have created more vg's then the
default rootvg.
If you only has the rootvg then there's one journal for the system.
> i.e. you can
> eject a ZIP disk with a VG on it and the VG on it will work elsewhere.
> AIX's JFS is restricted to the LV/VG universe (it starts calling you
> nasty names if you try to create one on just any old block device), so
> this scheme works well.
>
It's possible to do that to but with some odm hacking though :-)
>
> I don't think AIX makes any effort to load-balance the log between
> physical disks. It can't -- the size of the journal LV is the minimum.
>
The journal lv acts like paging lv's
which means you can change the size on it whenever you want, stripe it, let
it grow over
multiple disks etc.
>
> I agree that for load-balancing reasons it would be nice if ext3 moved
> in the direction of supporting journal-outside-fs and even a shared
> journal blockdev.
>
I must dissagre.
When you put it outside the fs you loose control of it.
I would like to see the journal on a fs and then a lv on top of it. (oh no
that sounded like AIX impl :) )
The question is why havent the LVM been integrated to 2.3.x kernels?
/joh
-- Code speaks louder than words.| ******* Josef Höök, Xinit AB ******** | | IBM Certified Specialist | | AIX System Administration | | SUN System Administrator | | phone: +46(0)60 120690, | | +46(0)70 6734576 | | mail: joh@xinit.se | | ************************************* |
--------------399E2FEF3072A3834FA95C23 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit
<!doctype html public "-//w3c//dtd html 4.0 transitional//en"> Peter Samuelson wrote:
[Dr. Michael Weller <eowmob@exp-math.uni-essen.de>]Thats statement is dependent on if you have created more vg's then the default rootvg.
> I mean, what you really want is: have the journal on a separate
> partition with no filesystem at all. Best of all on a seperate disk
> (controller, maybe). And you might want to have one journal only for
> all filesystems.AIX does this. There is one journal LV (logical volume) for each VG
(volume group). This (rather than one journal per whole system) is
because the VG is intended to be the unit of portability,
If you only has the rootvg then there's one journal for the system.i.e. you canIt's possible to do that to but with some odm hacking though :-)
eject a ZIP disk with a VG on it and the VG on it will work elsewhere.
AIX's JFS is restricted to the LV/VG universe (it starts calling you
nasty names if you try to create one on just any old block device), so
this scheme works well.
The journal lv acts like paging lv's
I don't think AIX makes any effort to load-balance the log between
physical disks. It can't -- the size of the journal LV is the minimum.
which means you can change the size on it whenever you want, stripe it, let it grow over
multiple disks etc.
I must dissagre.
I agree that for load-balancing reasons it would be nice if ext3 moved
in the direction of supporting journal-outside-fs and even a shared
journal blockdev.
When you put it outside the fs you loose control of it.
I would like to see the journal on a fs and then a lv on top of it. (oh no that sounded like AIX impl :) )
The question is why havent the LVM been integrated to 2.3.x kernels?/joh
-- Code speaks louder than words. | ******* Josef Höök, Xinit AB ******** | | IBM Certified Specialist | | AIX System Administration | | SUN System Administrator | | phone: +46(0)60 120690, | | +46(0)70 6734576 | | mail: joh@xinit.se | | ************************************* |--------------399E2FEF3072A3834FA95C23-- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.rutgers.edu Please read the FAQ at http://www.tux.org/lkml/