LTO bar code labels, Omniback, and stk L40

[Ian Bratko]

Environment: STK L40 library, 1 DLT8000 drive, 3 HP Ultrium2 drives, Omniback Ii 4.10.

From an HP whitepaper, the 7th and 8th positions on the LTO bar code label, the media identifier, are not used by Omniback. The labels on our initial batch of tapes have a media identifier of L1, even though they are LTO2 tapes, and they work fine. I am now ordering labels for additional tapes. If I start using labels with the correct media identifier (L2), will the L40 library have a problem handling tapes, some with media identifier L1 and others with L2? The labels would be unique to each tape using postions 1-6 of the label.

I want to buy tapes with L2 on the label. I just don't want to waste money on labels that would not work in our environment.

[Leif Halvarsson_2]

Hi,
OmniBack (and DataProtector) has only one Ultrium media type. From OmniBacks point of view it is no difference with Ultrium 1 or Ulrtium 2 medias, nor with the media labels. You can use both types of labels on any of the media (I have tried). I used a MSL 6060 library but I can't belive it should make any difference with STK L40.

PS
Of course it makes a difference with Ultrium 2 medias if you have a Ultrium 1 drive (it is not compatible) but OmniBack know nothing about the reason. The drive will just not accept the media.

[Ian Bratko]

As I should have done in the first place, I called STK support and the L40 library does process the media identifier. When the library sees the LTO1 (L1) identifier on my LTO tapes, the library shuts off streaming and other features on the LTO2 drives. This maybe part or all the explanation for why our LTO2 backups are not as fast as we thought they would be! I will be relabeling our tapes to the correct identifier and will post here what performance improvement we get.

[Jan de Vries]

Hello Ian,
This is very strange "the library shuts off streaming and other features". Can you be more precise?

[Jan de Vries]

LTO is a very fast drive, are you sure that host and source are capable of providing enough data to keep the drive busy?

[Ian Bratko]

I did not get the exact features that are turned off in the LTO2 drives when an LTO1 label is read. My primary purpose is to get the correct labels on the tapes. Your question is good, since it may help us sort out what our performance constraints may be. I will call STK support again.

I still suspect that we do not have the software/cpu/memory to drive the LTO2 devices, but it will be interesting to see if the label change has an effect.

I guess I should open a new question on what I can do to diagnose poorer-than-expected backup performance with LTO2.

(I intend to install HP's Tape Tools to see if it can help)