[ADSM-L] Update stgp devclass (Was Re: [ADSM-L] partitioning 3583)

2007-04-24 13:04:33
Subject: [ADSM-L] Update stgp devclass (Was Re: [ADSM-L] partitioning 3583)
From: Ray <rdejean AT GMAIL DOT COM>
Date: Tue, 24 Apr 2007 10:56:42 -0500

Thanks for the info, i appreciate it.  I did see in the operator guide that
the configurations are fixed, but i can deal with that.

I partitioned the library and put the two LTO-3 drives in Lib A.  The four
LTO-1 drives in Lib B.  The old device class was '3583'.  I created a new
devclass called '3583L3'.  Then created new libraries and checked LTO3
cartridges into Lib A, LTO1's into Lib B.  Now here's my problem:

I have a storage pool and LTO-3 volumes that are still device class '3583'.
But they're now in the Lib A LTO3 library.  Is there a way to change the
devclass on the storage pool or the volumes to '3583L3'??  Whenever the
storage pool needs one of the L3 volumes, it does a mount request thinking
the volume needs to be checked into Lib B (and of course the LTO-1 drives in
Lib B can't read the LTO-3 cartridge).

Of course i could wait for most of the data to naturally expire, but i think
there may be some long retention on some of the data.   Thanks for any


On 4/23/07, Prather, Wanda <Wanda.Prather AT jhuapl DOT edu> wrote:
Been there done that, all though it was quite a while ago.

You are correct that

- There is nothing in TSM code that will prevent TSM from trying to mount
an LTO3 cartridge in an LTO1 drive, if they are defined to the same TSM
library.  If you dig around in the books and web site you can find that
documented, but I agree it isn't intuitively obvious.

- The partitioning of the 3583 is limited to the  FIXED configurations
described in the 3583 Setup & Operator Guide topic "multipath library
configurations".  One place in the book sorta implies some flexibility, but
I checked with our regional tape specialist, and the configurations shown in
the book are the only ones available.  (There are also restrictions on how
the slots are divided up per logical library - if you have the 12-slot I/O
door, the 6 slots below the door ALWAYS go with lib A, for example.)

-Looks to me like you are correct that you will have 2 LTO3 drives in lib
A and the other 4 LTO1 drives in lib B, which means you will have to move
things around.

-In addition to creating the partitions, you must assign a CONTROL PATH to
the new logical library.  (Every logical library must have at least 1 drive
assigned as the control path.)  See in the book "add control paths".  Then
when you run cfgmgr, you should see a new /dev/smcx device.

-Everything else you have looks right.  Partition the library, reboot it,
run config mgr.  Make sure the devices show up in AIX like you expect.

Then for TSM you just create a new library, drives,  & paths in TSM on the
new /dev/smcx device, check the tapes in to that library.  Update the
paths/drives in the old library defined on /dev/smc0.  TSM thinks it's 2
real, physically separate libraries.

Things to check on:

--Early releases of the 3583 didn't have the "multipath" feature, which
means you can't partition.  If you don't find the right virtual buttons on
your front panel, you probably need to upgrade the microcode, although I'm
pretty sure you have to be reasonably current since you are running
LTO3's.  (I'd recommend getting up to date on the microcode, anyway.)

-Make sure you are using a reasonably up-to-date version of the Setup &
Operator guide.

Once you get past the frustration of having to use the fixed partitions
you get, it works like a champ.



From: ADSM: Dist Stor Manager on behalf of Ray
Sent: Mon 4/23/2007 3:18 PM
Subject: partitioning 3583


Through a little confusion and lack of research, we have a 3583 library
where we have mixed LTO1 and LTO3 media.  Apparently we read that TSM and
the 3583 supports "mixed-media with LTO" and didn't read the fine print,
thinking it would just work.  The drives and cartridges are in a single
device class (format=drive) all in the same storage pool.  Surprisingly
has been working fine for a few months.  I have 4 LTO-1 drives in slots
and 2 LTO-3 drives in slots 5-6.

After a backup failure, i noticed TSM trying to mount an LTO3 cartridge in
an LTO1 drive.  Further research showed that our setup should not work at
all haha.  I've determined the best course of action now is to partition
into 2 logical libraries.  One library for LTO-1 media, one for LTO-3
media.  Having never done this before, i have a few questions.

1.  Are the 3583 partitioning configurations "fixed"?  I don't see a way
assign a particular drive to a particular partition.  If it is a fixed
config, then according to the operator guide, when you define 2 logical
libaries, drive slots 1 and 2 are in library A, and slots 3-6 are in
B.  If this is true, i'll have to physically move the LTO-3 drives to
1 and 2.   Am i following this correctly?

2.  Library is connected to a p5-570 running AIX 5.3.  Right now the
is /dev/smc0.  After partitioning, will i get a smc0 and an smc1?  Should
run cfgmgr after partitioning?

3.  What is the best procedure to do the partition?  I'm thinking i need
checkout all the cartridges, then turn off the library.  Move the tape
drives, then partition the library.  Then deal with the AIX devices
(rmdev/cfgmgr).  Then redefine drives/paths, define new device classes and
checkin the cartridges to the right logical library.  Am i missing

We're running TSM  Thanks for any info.  I appreciate it.

Ray DeJean                              <>
Systems Engineer                    Southeastern Louisiana University
IBM Certified Specialist              AIX Administration, AIX Support

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