Retrospect not correctly showing tapes

[speleo14]

I recently moved my backup from an XServe with 10.6.8 (SAS PCI card) to a MacPro running 10.11, and now I'm having problems with Retrospect's connection to my tape libraries.

My setup: MacPro Late 2013, Atto Thunderlink SH2068, Quantum Scalar i40 (LTO-4), Quantum Scalar i80 (LTO-6), each equipped with 2 tape drives. Mac OS 10.11.0, Retrospect 12.5.0.

 

It now happens very often that, for example, LTO-4 tapes are shown in the LTO-6 library (I can see that by the barcode, using <1000 for LTO-4 and >1000 for LTO-6), sometimes the tapes are even "mixed", i.e. some tapes in the same library are LTO-4, some are LTO-6 - which of course they are not, it's just Retrospect wrongly showing them this way.

Tapes are being shown as "in drive" when they are not, or a drive is shown as empty when it has a tape in it. When I try to initiate a scan, nothing happens, I need to restart retroengine or even the MacPro, often several times, to get Retrospect to pick up the tapes in my libraries correctly. Thus, my backups often stall because Retrospect doesn't find the appropriate tape to continue. I didn't have that problem before when still on the XServe.

See attached screenshot: Slot 67 is shown as "in drive", whereas both drives are shown as "no media". As a matter of fact, there definitely IS a tape in slot 67, namely tape No. 1079 (according to the website of the tape library and checked physically).

 

Any ideas?

 

Thank you,

 

Tina

[speleo14]

Update:

 

In addition to the 2 tape drives, I had an external HD (LaCie d2, 4TB) attached via Thunderbolt to the Mac Pro, which somehow seemed to have an unstable connection (unmounted itself every few days). I have now connected this HD via USB instead of Thunderbolt, and ever since, the unmounting of the drive stopped and also the tapes seem to be shown & found correctly (keeping my fingers crossed).

 

Note: I used 2 different external HDs, same brand & model as well as several different Thunderbolt cables and 2 different Mac Pros, and I always saw the same behaviour. Thus I don't think that the issue was with a faulty drive, cable or Thunderbolt bus, but rather the Thunderbolt connections to the HD and to the Atto Thunderlink somehow interfering (Thunderlink driver issue or Retrospect or OS??).