MSL5052SL and MSL5052S2

[Daniel Pilloff]

Currently we have both the MSL5052SL and MSL5052S2 on our fabric. We use Backup Exec 8.6. My question pertains to the interoperability of the 110/220 format on one library and the 160/320 format on the other library. Is there a way to ensure that all the tapes are formatted and written to as 110/220 tapes. I thought I read somewhere that along with backwards compatibility for reading, the SDLT 160/320 was capable of writing in the 110/220 format. There is a setting on the web based utility to accomplish this but when we tried using formatted tapes at 110/220 in the 160/320 library we were unable to put these tapes back in a 110/220 drive without getting the error in Backup Exec "bad media". Does anyone have experience with this issue?

[David Ruska]

Media compatibility:

** Super DLTtape I
160 or 110 GB native capacity

** DLTtape IV - read only in SDLT 220
20, 35 or 40 GB native capacity

Here's quauntum's compatability chart:
http://www.quantum.com/am/service_support/compatibility/dlttape_media_compatibility_matrix.htm

> There is a setting on the web based utility to accomplish this but when we tried using formatted tapes at 110/220 in the 160/320 library we were unable to put these tapes back in a 110/220 drive without getting the error in Backup Exec "bad media"

The host (via SCSI Mode Select) has the ability to select the tape density when writing to tape. I can guess that you have access to this through the Device Properties -> Media Types tab in BUE. The manual says you can control which formats it can read and write. See if there's a selection for 110/220 for writing (and disable 160/320).

[Daniel Pilloff]

thanks for the reply, I am not exactly sure what is meant by "guess that you have access to this through the Device Properties -> Media Types tab in BUE". If you mean that in Backup Exec (BUE) there is a place to establish the tape format I have not been able to find it. On the other hand, if you meant somewhere else we do have the ability to change the tape density through the web console and have been able to do it. The main concern is that although the literature as you referenced lists the tape formats and their compatibilty, up to this point everything we have tried has not worked. Presently I have a ticket open with HP and the issue was bumped up to two tier 2 technicians. But we'll take any suggestions, thanks again for your reply

[David Ruska]

> If you mean that in Backup Exec (BUE) there is a place to establish the tape format I have not been able to find it.

Yes, I meant Backup Exec. I know the media types tab is in the device properties in BUE 9.1. I noticed you're using 8.6, so perhaps its different.

I'm asking engineering about using the web interface for selecting the format. However, if the host software does a mode select for tape density, it may override what the web interface selects.

Are you starting with an unformatted tape?

[Daniel Pilloff]

thats very interesting about BE 9.1, we just started in our test lab environment installing and configuring it, looks like there are some new features we will be able to hopefully take advantage of. I believe we tested both (formatted and unformatted) and I am positive we tested formatted, but to be on the safe side I will go ahead and test unformatted again. If the host software, in this case BE 8.6 which does not appear to be configurable, overrides the web settings then if I am reading this right we may be out of options until we upgrade to BE 9.1. Unless there is another way to select the tape drive format.

[Curtis Ballard]

Writing in an older format is always a tricky issue when a backup application doesn't specifically support it.

A few pointers
- None of the (S)DLT drives will allow changing format or compression once anything is written to a tape. Some people have reported success with changing the settings when at beginning of tape but I have only been successful after a complete erase.

- Watch out for device drivers. I can't speak for the BE 8.6 drivers but some drivers will always force the drives to write in highest capacity with compression.

- Often the easiest solution is to initialize all your tapes in the lower density drive then move them to the higher density drive. As long as you don't reformat the tape they should stay in low density mode.

[Peter van den Berge]

The problem loooks familiar to me.
We have a mixed MSL5052SL with two 110/220 SDLT drives and one 160/320 drive. When a tape has been used in the 160/320 and it will be used in the 110/220 drive, we received the message "bad media" in Backup Exec (version 8.6).
Have you already fixed your problem and if so, can you tell me how I can fix my problem?