Turns out there is a catch, we have to "virtualize" the robot for NBU using
"SDLC" to fool NBU into thinking there are two robots, when there is only
one device.  It's not as simple as tape types, we have to dedicate certain
imp/exp slots and tape storage slots to the new storage unit and set up
separate "scratch" pools for Operations. Eww.

-----Original Message-----
From: Larry Kingery [mailto:larry.kingery AT veritas DOT com] 
Sent: Sunday, September 21, 2003 12:15 PM
To: Aren.Parisi AT wwireless DOT com; veritas-bu AT mailman.eng.auburn DOT edu
Subject: [Veritas-bu] question for you re: one scalar10k library with 20
total drives , one robot, 10-drives = LTO1, 10-drives = LTO2



> NBU 3.4.1, HP-UX 11i masters in a 3-way Veritas ClusterManager 
> cluster, the master is also currently the media server, that may soon 
> change. Library is an ADIC Scalar 10k currently has 10 - IBM magstar 
> LTO(1) drives, we are adding 10 additional drives, but these are 
> LTO-2.  Because of the forward incompatibility we will have with the 
> LTO2 tapes possibly being used on an LTO(1) drive, which will fail and 
> cause frozen tape snarls, it looks like we need to set up another 
> storage unit for the new drives, as well as another volume pool for 
> the LTO2 tapes. My question is: can anyone describe the "locking" 
> mechanism in NBU by which simultaneous requests to the same robot 
> which minds two different storage units are managed?  Is this a 
> "gotcha"? Is this a "don't do that"?  Will we just get a bunch of 219 
> storage unit unavailable errors or is this supported? Has anyone else 
> attempted to do this?  Thanks all!
> 
> 

No problem here.  This is exactly why you have multiple types such as hcart,
hcart2, and hcart3.  Pick a new type for the new drives and configure new
tapes, drives and storage units using the new type.  NBU will NOT mix tape
types and drive types, for example it will not put an hcart tape in an
hcart2 drive.

The only downside is that if all your LTO1 drives are busy, you can't use an
LTO2 drive to read an LTO1 (written) tape, even though the LTO2 drive could
be used to read the tape (I think -- I'm assuming that LTO2 can read LTO1,
if not substitute DLT7000 and DLT8000 in this example).  


-- 
Larry Kingery 
         Error: Keyboard not attached. Press F1 to continue.