It is best practice to put one initiator and one target in each zone.  It
may seem cumbersome but its really not that bad.  You'll be happy you did
it if you ever have SAN problems down the road.  I have seen one device
take out all other devices within the same zone before, more than once.
Just pick a good naming convention for your zones so you can tell exactly
what is in each zone just from the name.  I also prefer to use aliases so
when you replace a HBA or tape drive you just update the alias with the
new PWWN instead of going in and changing 20 different zones.


***Please note new address, phone number, and email below***
______________________________
John Monahan
Consultant
Logicalis
5500 Wayzata Blvd Suite 315
Golden Valley, MN 55416
Office: 763-417-0552
Cell: 952-221-6938
Fax:  952-833-0931
John.Monahan AT us.logicalis DOT com
http://www.us.logicalis.com




"Schneider, John" <schnjd AT STLO.MERCY DOT NET>
Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
02/06/2007 05:05 PM
Please respond to
"ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>


To
ADSM-L AT VM.MARIST DOT EDU
cc

Subject
Tape drive zones for FC drives - best practices






Greetings,
        My habit in regards to zoning FC tape drives has always been to
put
one host HBA in a zone with all the tape drives it should see, and to have
a
separate zone for each host HBA.  For example, in a situation with 2 host
HBAs and 10 tape drives, I would have two zones, one with one host HBA and
5
tape drives, and the other with the other host HBA and 5 tape drives.
Pretty simple.

        But an IBM consultant working here is telling me that the best
practice is to have a separate zone for each HBA/tape drive pair.  So in
my
example above, I would have 20 zones instead of two.   His claim is that
an
individual tape drive can hang all the other drives if they are in the
same
zone, but not if they are in separate ones.  Has anyone seen this in real
life?

        This becomes important to me because I am about to put in new SAN
switches, and he wants me to follow this recommendation.  I have 2 TSM
servers with 4 HBAs each, 4 NDMP nodes, and 14 tape drives.  Using my
scheme, I would have 12 zones, with his scheme I would have 56 zones. That
seems like a lot of zones, and unnecessarily cumbersome.

        Is it really necessary to isolate each HBA/Tape drive into a
separate zone?  Do individual tape drives really hang other drives in
their
zone?

Best Regards,

John D. Schneider
Sr. System Administrator - Storage
Sisters of Mercy Health System
3637 South Geyer Road
St. Louis, MO.  63127
Email:  schnjd AT stlo.mercy DOT net
Office: 314-364-3150, Cell:  314-486-2359