RE: Upgrading disks

Mark,

The model 400 has four disk slots in the system unit, driven by the
MFIOP, and eight disk slots in the expansion unit, driven by a RAID
controller.  The MFIOP does not support RAID.  If your client has all
twelve slots filled and they are all protected, it is more likely that
they have two pairs of mirrored disk and a RAID set of eight drives.

Data can be pumped, but this would involve turning off the disk
protection for the duration, then turning it back on once all of the 2GB
drives were replaced with 4GB drives.  For instance, you could turn off
RAID, then do a logical remove of one of the drives.  This would move
the data from that drive to the others so that it could be removed.
Then you could replace that drive with a larger one.  Repeat as
necessary until they were all replaced.  As you added the larger drives,
you would end up with more free space so that you could remove more than
one drive at once.  Depending on their need for more space, they may
choose to not replace their mirrored boot disk.

I think this is awkward and your client might be better served by
replacing all drives at once and restoring the system.  In the pumping
scenario, the drives would definitely need to be rebalanced so that data
was properly spread.

The SAVSTG command should work provided that you have the same (or
larger) disks in the same configuration.  The text below is from the
Backup and Recovery manual (V5R1):

"The disk configuration of the restoring system must be the same as the
disk configuration of the saving system. There must be at least as many
disk units on the restoring system as there were on the saving system.
Each disk unit capacity on the restoring system must be equal to or
greater than the capacity of the disk unit on the saving system. Serial
numbers and physical addresses do not have to be the same. All disk
units that were saved are required for the restore operation.

If your system has mirrored protection now, when the restore storage
procedure runs, your system will not have mirrored protection on any
Auxiliary Storage Pool (ASP)."

My preference would be to reload from a SAVSYS.  It strikes me as a
simpler procedure, although it will require more time for the reload and
will result in a loss of spool files.

Regards,
Andy Nolen-Parkhouse

> -----Original Message-----
> admin@midrange.com] On Behalf Of M. Lazarus
> Subject: Upgrading disks
>
>   A client would like to upgrade their disks in an old system (model
> 400).  They currently have 12 x 2GB disks.  There is one pair that is
> mirrored and the rest are RAID'ed.  Since there are no available bays,
> if
> they wanted to double or almost double the size of their disk space,
> what
> would the procedure be to transfer the data?
>
>   Can the data be "pumped" somehow or does a full system restore need
> to be
> done?  If the latter, can a SAVSTG be done?
>
>   TIA.
>
>   -mark