On Mon, 13 Oct 2008, Orin Rehorst wrote:

> Our TSM was set up to nightly:
>
>       1. backup the VTLpool to copypool
>       2. backup the tapepool to copypool
>       3. migrate stg VTLpool (to tapepool)
>
> Step 2 is tape-to-tape and therefore slow.
>
> Could I change to eliminate the tape-to-tape and still get the job done?
>
> For example:
>
>       1. backup the VTLpool to copypool
>       2. backup the VTLpool to tapepool
>       3. migrate stg VTLpool (to copypool)

If "tapepool" is a primary pool, you cannot backup the disk pool to
it.  You can only backup to a storage pool of type "copy".  I assume step
3 is a typo, as you cannot migrate a primary disk pool to a copypool.

As a good practice, you should always issue a backup stg command of your
primary tape pool to the copypool to ensure all your data is in the
copypool.

Your original steps are correct.  Just wait to start migration until step
1 completes, minimizing the amount of data that may have to be copied tape
to tape.  You should still run the process for step 2.  If there is a lot
of data being copied, check the maxsize setting on your VTLpool, and check
if your VTLpool may be filling during backups, and forcing migration prior
to running the backup in step 1.


Hope this helps.

Steve Roder
University at Buffalo
(spr AT buffalo DOT edu | (716)645-3564)