I had similar issues with an STK L180 library, and it came down to bad firmware 
on the library.  Have you checked to make sure you're running the same level on 
both libraries?  It should be viewable on the front panel.

What are the symptoms when it goes offline?  Is the front panel still 
responsive?  Are there scsi sense codes from the robot device?

----
Daniel Murphy-Olson
Systems Administrator
Mathematics & Computer Science Division
Argonne National Laboratory
630-252-0055

----- Original Message -----
From: "John C. Dury" <JDury AT DUQLIGHT DOT COM>
To: ADSM-L AT VM.MARIST DOT EDU
Sent: Tuesday, April 5, 2011 5:10:47 PM
Subject: [ADSM-L] nightmares with a STK SL500 tape library

We purchased an STK SL500 tape library with 4 LTO4 drives in it a few years ago 
and we have had nothing but problems with it, almost from the beginning. It is 
fully loaded with LTO4 cartridges (about 160) and seems to randomly just crash 
and take all of the drives offline to TSM. We also have a second SL500 that is 
at a remote site and connected to the same TSM server , and it has no problems 
at all. The remote SL500 has copies (backup stg pool) of the local SL500. We've 
gone round and round with STK/Oracle support and they have actually come onsite 
and physically replaced the entire robot and all of it's parts, several times 
and they can never find a reason as to what is causing it to go offline. Keep 
in mind this has been happening about once a month or so for over a year.

My questions to all of you is not so much what could be wrong (although if you 
have ideas, that would be great also), but, we are considering a new robot and 
are hoping to be able to use or reuse our existing LTO4 tapes. Right now it has 
about 80 scratches so if we were to goto a second library, I should be able to 
have both defined to TSM and move the data from one to the other after putting 
some of the scratches in the new library and labeling/initializing them until 
all data is in the new library and then I can light the old one on fire (j/k) !
Like most IT departments we are severely budget constrained so we would like to 
reuse the tape drives and the tape cartridges and only purchase a robot that 
can handle 160 slots or so. Suggestions if this is even an option or which 
robots and/or models to look at? Remember, very little budget for this if I 
could even get it approved at all but we really don't know what else to do with 
the bad SL500 at this point and we have a project coming up that is going to 
increase the amount and flow of data to our TSM system significantly within the 
new few years.
Help!
John