Re: Multiple Guested LPARS Backup Approach

I have a tape library with six drives. All fiber. Each drive has a fiber
cable to the SAN switch.
I have a Power 6 with 5 lpars. Each lpar has it's own fiber card.
One of the lpars is Linux and runs Tivoli Storage Manager. It's tape
heavy. It's running all day doing things like combining multiple tapes
into one, etc. Therefore it has 3 of the tape drives 'zoned' to it via
the SAN.
The lpars of IBM i all have the other 3 drives zoned. Four lpars of IBM i
share three drives. Looks like
WRKMLBSTS
Device/
Resource Status
TAPKVL01 VARIED ON
TAP03 OPERATIONAL
TAP01 OPERATIONAL
TAP02 OPERATIONAL

The library itself is divided up into two logical libraries.

I load up 7 days worth of tapes every Monday but we only backup 5 days of
the week. The extra is to be ready in case of holidays and to have extra
tapes in case one lpar starts using more tapes.
I use the STRBALBRM ACTION(*SET) to allocate how many of the tapes each
lpar uses during that 7 day period.
I use the STRBALBRM ACTION(*BALANCE) to spread the tapes out between the
lpars. And verify it with STRBALBRM ACTION(*REPORT).
Normally you don't have to be too anal about balancing the tapes out if
you're using the network feature. BRMS will borrow from other lpars if it
can talk to them and ask them nicely. However, I balance them anyway
because if you're doing a save in restricted mode and both lpars are
restricted it can't strike up a conversation. If only the consuming lpar
is restricted it may start just enough tcp to be able to strike up a
conversation.

Since I have three drives shared by four lpars I do have to be careful to
not do backups on all four at once. We do some extensive logging to keep
track of start/stop times just to plan our actions if it's getting close
to overlapping.


Rob Berendt