ADSM-L

Re: [ADSM-L] Mixing drive types in logical library 3584

2007-06-02 03:37:28
Subject: Re: [ADSM-L] Mixing drive types in logical library 3584
From: Steven Harris <steve AT STEVENHARRIS DOT INFO>
To: ADSM-L AT VM.MARIST DOT EDU
Date: Sat, 2 Jun 2007 16:32:34 +1000
Hi all,

I recently tested a TS3310 library - using 8 char tape labels.
It had only LTO3 drives but two devclasses, one for lto2 and one for lto3.

When loaded with a mix of LTO2 and 3 tapes it chose the correct scratch tape
for the job, based on the devclass being used.

I don't know and couldn't test whether this works the other way.  One thing
to be careful of is that you can run out of scratch tapes of one sort or the
other, the operation fails, but TSM OR and the usual home-grown selects will
show that there are scratches in the library - so you need to be a bit
smarter with your scratch management.

Regards

Steve
Steven Harris,
AIX and TSM Admin
Brisbane Australia

Soon moving to Sydney -  any job offers gratefully received.

-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of
Prather, Wanda
Sent: Saturday, 2 June 2007 5:03 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: [ADSM-L] Mixing drive types in logical library 3584

(snip)..our information is that TSM is smart enough to mount LTO media only
in drives appropriate to the operation (so LTO2 media will only mount in an
LTO4 drive if it's being read, not written;
LTO4 media will never be mounted in an LTO2 drive; etc.) So if you were to
add LTO3 media to that library down the road, TSM would access it only
through the LTO3 drives (and if all the LTO3 drives were being used with
LTO2 media while an LTO2 drive sits idle, too
bad.)

Can you tell me where you got that information?
Seems to me that coflicts with the statement in IBM technote 1155662.
"However, mixing LTO-1 and LTO-3 is not recommended because LTO-3 drive can
read but cannot write to LTO-1 media".

If you have LTO2 carts checked in to the library, and LTO4 drives, what is
to keep TSM from trying to mount one of the LTO2 carts in the LTO4 drive for
WRITE?




--
No virus found in this incoming message.
Checked by AVG Free Edition.
Version: 7.5.472 / Virus Database: 269.8.5/826 - Release Date: 31/05/2007
4:51 PM