So that might have been my problem (but not necessarily limited to that
one).

I was on Suse 10 system.  I initially stripped the LVM.  When it got nearly
full, I tried to add a pack.  Couldn't do it.  So I went back and recreated
the LVM without striping and I could add a pack.  I want to say that the
documentation at that time, also said you couldn't add packs to a striped
LVM, but that was a while ago.

Anyway, it hasn't been a performance issue.  But that is due to us not
needing the I/O performance.

Thanks for the update.  I'm updating my notes.

Tom Duerbusch
THD Consulting

On Wed, Oct 10, 2012 at 12:53 PM, Mark Post <[email protected]> wrote:

> >>> On 10/10/2012 at 11:35 AM, "Duerbusch, Tom" <[email protected]>
> wrote:
>
> > Just speaking to LVM...
> >
> > Striping the data across multiple volumes (which in modern dasd is
> already
> > stripped in the Raid array), would give you the best performance.
> >  Especially if you can strip across multiple DS8000 (or other dasd
> > subsystems).
> >
> > But you can also use LVM as a pool of DASD, with no striping involved.
> >
> > In case 1, if you need to expand the LVM pool, it is a hassle.  It might
> > mean backing up, reformatting and reloading the data.  In any case, it
> > involves a knowledgeable person and most likely, downtime.
>
> This is simply not true.  Expanding a striped LV can be done dynamically
> with no downtime.  The only aspect that is different from a non-striped LV
> is that you have to have enough free space on as many different PVs as the
> number of stripes you have.  That is, if you did an "lvcreate -i 2" then
> when you do an lvextend/lvresize, you have to have free space available on
> 2 different PVs in the pool.  An "lvcreate -i 3" means you need free space
> on 3 PVs, etc.
>
> A lot of people tend to add space to a volume group one PV at a time.  If
> you're using striped LVs, that won't work unless you make sure that the
> existing PVs have enough free space on them to accommodate additional
> stripes being allocated.
>
>
> Mark Post
>
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