I personally think it's worth the effort, not so much for the fail-over but for 
the fact the Atape driver will do some HBA load balancing for you to maximize 
performance across less utilized HBA ports. We do have a few ProtecTier's in 
the mix and also a Windows 2008R2 based LAN Free server, the LF server actually 
utilizes some of this redundancy as well and the IBM Tape driver load balancing 
as well. For the VTL based devices what we typically do is rename the rmt 
entries in AIX based on their serial number since they've typically been just 
different drives behind the same front end WWPN's.

We're running 60 physical LTO5's and 128 emulated LTO3 devices from the PT for 
comparisons sake. With some scripts work wise it isn't too much more effort.


----- Original Message -----
Is it worth the work?
Are there any VTLs involved?

I may be doing 4 TSM servers to 18x 3952's, 8x LTO6 shared drives and 120x 
LTO1's for each server non-shared in multiple DataDomains. I also have LANFree 
clients that do not support redundant fabrics.

Thank you,

Andy Huebner


-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of 
Mike De Gasperis
Sent: Wednesday, February 26, 2014 8:44 AM
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: [ADSM-L] Redundant Tape SAN

We utilize a redundant tape SAN at our main data centers with multiple host 
site HBA ports. Using the Atape control and data path fail-over options we have 
twelve device entries for each physical tape device. Works really well and this 
is in an AIX/LPAR/VIO environment, we've virtualized the HBA ports and are 
using NPIV. We have some scripts created that rename each rmt entry via chdev 
to utilize the last four digits of the WWPN and the AIX fiber channel adapter 
to make things easier to line up as well when defining drives in TSM.

----- Original Message -----
Is anyone using redundant tape SAN with TSM on AIX?

Andy Huebner