"Andreas Schulze" <b79xan@gmx.de> wrote in message
news:cnkteo$mfo$1@tgx093.str.allianz.de...
> "Jeffrey Ross" <jeffrey.rossATairways.co.nz@no.spam> schrieb im
Newsbeitrag
> news:419d2482$1@news.iconz.co.nz...
> [some snipped]
> >
> > Now I come to my question (for those who are still reading).
> |-)
> >
> > My mirror is as shown below, with the upper disks (or actually their
> logical
> > volumes) mirrored to the lower ones:
> >
> > pdisk0 pdisk1 pdisk2 pdisk3 pdisk4
> >
> > pdisk5 pdisk6 pdisk7 pdisk8 pdisk9
> >
> > I found that the logical volumes on pdisk1 are mirrored to pdisk7, not
> > pdisk6 as expected, and correspondingly pdisk2 is mirrored to pdisk6.
The
> > pdisk order matches the physical slots that the disks are in (which is
> what
> > I want), so swapping the disks isn't the right solution. What I have to
> do
> > is swap the logical volumes between pdisk6 and pdisk7. This wouldn't be
a
> > problem except that pdisk6, pdisk8, and pdisk9 are each 36GB and
comprise
> > one large logical volume. I can split the mirror for pdisks 6, 7, 8,
and
> 9,
> > reform it with the right file systems on the right disks, but the syncvg
> > will take 5 hours and the processor will be almost permanently in wait
> state
> > during that time. We are a 24 hour air traffic operation, wishing to
> > minimise risk of application down-time. Is there a way of swapping the
> file
> > systems on pdisk6 and 7 without having to re-sync the whole of pdisks 8
> and
> > 9 as well?
> >
> > Probably asking too much...
> >
> > Thanks anyway,
> >
> > Jeffrey.
> >
> Hallo Jeffrey,
>
> Syncing is done on volumegroup level but you can tell syncvg to
synchronise
> up to 32 PP in parallel. Defaults to 1 and that is why it takes
soooooooooo
> long. You might need some testing to find out how many PP can by sync'd in
> parallel on your fs to find an optimal value. Start with say 8 and you
will
> be surprised positively how much faster syncing will take place. Secondly
> you could use syncvg in the background by simply issuing a varyonvg
> <yourvg>. Either way should alleviate moving the lvs around.
>
> HTH,
> Andreas
>
Thanks, Andreas.
That's an option that I didn't spot. Will do some testing using it.
Much appreciated,
Jeffrey.