"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