RE: Disk upgrade with no downtime - possible?

Not without any down time. Can you add drives without removing? If so,
you can add the drives and move data off the old drives. You basically
need to do a raid set at a time. If you have enough free space you can
deallocate 5 drives then boot to DST to remove which is really quick
when there is no data on them.

Check out the command STRASPBAL:
*CAPACITY
*USAGE
*HSM
*MOVDTA
*ENDALC
*RSMALC

*ENDALC will make your system stop using the drives and *MOVDTA will
attempt to move the data off the drives that have the *ENDALC.

**WARNING you must have enough free space to absorb the data.

Once you are in DST and LOGICALLY remove the drives, you shut down and
then PHYSICALLY remove the drives and replace with the new drives.

Down time is minimal but required.

Also you cannot replace a drive in a raid set with a drive of different
capacity. (Hey I tried on an old system we replace to see if I could do
it on our production system. Failed miserably ;-(




Chris Bipes
Director of Information Services
CrossCheck, Inc.


-----Original Message-----
From: midrange-l-bounces@xxxxxxxxxxxx
[mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of Pete Helgren
Sent: Wednesday, March 11, 2009 7:30 AM
To: Midrange Systems Technical Discussion
Subject: Disk upgrade with no downtime - possible?

Seems like I have either asked or seen this before but I am planning to
upgrade 5 out of 10 disks allocated to an LPAR which is currently at
86%. My goal is to hopefully replace the drives while the partition is
active so the question is: Can I replace the drives one at a time and
just allow RAID-5 to rebuild the drives?

The info center for V5R4 says this:

"A disk unit that is running with device parity protection can be
exchanged only if it has failed. A disk unit running with device parity
protection cannot be replaced with a non-configured disk even if it has
failed."

So it sounds like I *can't* do it.

Any pointers here? Seems like I should be able to just replace each
disk one at a time and let then it rebuild before replacing the next
one, but having only replaced truly failed drives, I am in uncharted
territory.

The existing drives are model 4326 type 072 (30GB) and I plan to
replace them with 4327 (70GB). V5R4M0 9406 520

Pete