Re: [ADSM-L] partitioning 3583

2007-04-23 18:04:32
Subject: Re: [ADSM-L] partitioning 3583
From: "Prather, Wanda" <Wanda.Prather AT JHUAPL DOT EDU>
Date: Mon, 23 Apr 2007 17:49:45 -0400
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 
-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 this
has been working fine for a few months.  I have 4 LTO-1 drives in slots 1-4,
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 to
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 library
B.  If this is true, i'll have to physically move the LTO-3 drives to slots
1 and 2.   Am i following this correctly?

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

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

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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