LTO3 and LTO4 tapes in a LTO4 "library"

[Stephan]

Hi.

We are migrating to a new library with all LTO4 drives. I created a Device Class for LTO4s and labeled some tapes. I'd like though, to use my LTO3s for long term vaulting such as backupsets...

I thought, i'd create a LTO3 devclass, then when generating the backupset with the option deviceclass LTO3 that i would mount a LTO3 tape and write to it...But no.

The behavior i am seeing, is that it mounts every single LTO4 scratch tape, fails on it and puts it in a "private" status to prevent reuse...! Then, when it finally reaches a LTO3, it starts...It seems to grab the LTO4 first, since the are numbered for example 110000L4 whereas the LTO3 are 700000L3. So it looks like it grabs the "smallest" numbered tapes first...

So, what are Device Class for then? I thought, that when labelling the tape, TSM would "know" that he just labeled a LTO3 thus picking one up right away when i specify to use LTO3 devlclass?

If not, apart from scripting it...any ideas?

Thanks.

[JeanSeb]

Could you post "q devc f=d" just to eliminate the obvious ?

[Stephan]

Sure thing...! Are you doing something similar?


Device Class Name: T950_LTO3_DEVCLASS
Device Access Strategy: Sequential
Storage Pool Count: 0
Device Type: LTO
Format: ULTRIUM3C
Est/Max Capacity (MB): 819,200.0
Mount Limit: DRIVES
Mount Wait (min): 30
Mount Retention (min): 2
Label Prefix: ADSM
Library: T950
Directory:
Server Name:
Retry Period:
Retry Interval:
Shared:
High-level Address:
Minimum Capacity:
WORM: No
Drive Encryption: Allow
Scaled Capacity:
Last Update by (administrator): DURS
Last Update Date/Time: 01/18/2010 08:45:28

Device Class Name: T950_LTO4_DEVCLASS
Device Access Strategy: Sequential
Storage Pool Count: 1
Device Type: LTO
Format: ULTRIUM4C
Est/Max Capacity (MB): 1,638,400.0
Mount Limit: DRIVES
Mount Wait (min): 30
Mount Retention (min): 2
Label Prefix: ADSM
Library: T950
Directory:
Server Name:
Retry Period:
Retry Interval:
Shared:
High-level Address:
Minimum Capacity:
WORM: No
Drive Encryption: Allow
Scaled Capacity:
Last Update by (administrator): DURS
Last Update Date/Time: 01/18/2010 08:46:11

[JeanSeb]

Sure thing...! Are you doing something similar?

I do, but did not experience the same problems.
I just thought maybe your entered the wrong Device type in your class...
Aside from that, I don't know, sorry

[rallingham]

I seem to recall when testing TKLM (encryption) that LTO4 drives cannot encrypt LTO3 tapes. This may be an issue for you if you are using Drive Encryption. Or it may not be related to your issue at all. Have you tried turning off encryption and then running your process?

[GregE]

Stephan, Chapter 5 of this redbook has some excellent info on mixed generation implementations. Around page 215...
http://www.redbooks.ibm.com/abstracts/sg246502.html

Someone in this forum had a long thread going a few months back. Almost positive it was Mikeymac, and this thread, which is not as it once was, with "****muzzled****" all over it for some reason.
http://adsm.org/forum/showthread.php?t=17196

[Stephan]

Thank you for the information. I will go ahead and give that redbook a look. I've also placed a support call with IBM...We'll see what they say.

rallingham: I did notice that drive encryption is "allowed" in my config...Don't know if it would do anything by will try to change it to see...

Thanks.