DPMLA service restarting - Tape

Question

Hi, we're having issues with our HP G3 tape library. First of all we notice that the tape library and drive sometimes appears twice after a rescan (once the real library and drive, once as standalone). The standalones can be removed by removing them from
all the tables in the database but they re-appear after some time (and some rescans). This also happens when I use the DPMLA.xml file for manually remapping the library and drive.
A few times per day I can see that the library is stopping and it gives error "Stand Alone Drive Tape Library Hewlett Packard LTO Ultrium-4 drive is not ready. (ID 25014)" After that no backups succeed until we manually rescan the library.
After some troubleshooting and playing with drivers, manually remapping, scsi registry settings and all we could think of I found out that this actually happens because of the DPMLA service that stops and restarts at that moment. In the LAAgent error log
I see the following at that moment (I don't know if it's during a tape backup or just between two tape backups):
21A8    1B4C    05/19    15:13:18.293    05    genericagent.cpp(266)    [000000000029AE50]        NORMAL    Agent Can
Shutdown if there is only default wokitem active[1]
21A8    1B4C    05/19    15:13:18.293    03    workitem.cpp(391)            NORMAL    Timing out WI [00000000008C6A30],
WI GUID = {B71B4544-7067-4A30-B5FB-BA320B10D82A}, ..last DM activity happened 354236484msec back, WI Idle Timeout = 390000msec
21A8    1B4C    05/19    15:13:18.293    22    genericthreadpool.cpp(684)    [00000000008E7CF0]        NORMAL    CGenericThreadPool:
Waiting for threads to exit
21A8    12BC    05/19    15:13:19.715    03    service.cpp(147)    [000000000017F660]        ACTIVITY    CService::ServiceHandlerExInternal
21A8    1B4C    05/19    15:13:20.309    22    genericthreadpool.cpp(684)    [0000000000827FD0]        NORMAL    CGenericThreadPool:
Waiting for threads to exit
21A8    10E8    05/19    15:13:22.324    03    timer.cpp(513)    [000000000089CB68]        ACTIVITY    Shutting down timer
thread.
21A8    1B4C    05/19    15:13:22.324    03    service.cpp(81)            ACTIVITY    CService::StopThisService
21A8    1B4C    05/19    15:13:22.324    03    service.cpp(281)    [000000000017F660]        ACTIVITY    CService::StopService()
So it appears DPM is shutting down the service itself because some timer has expired. Does anyone know how this works or how I can prevent this? Also I'm trying to figure out what Work item with GUID B71B4544-7067-4A30-B5FB-BA320B10D82A is and if this has
anything to do with it.

Answer 1

Hi Kevin, Ok thanks for the feedback. Unfortunately I have no good suggestions since I have also been unable to resolve the issue. 
I actually had two separate external tape devices connected to the DPM server. One was a HP autoloader with an LTO drive and the other a HP LTO stand-alone tape drive. The stand-alone drive is not used by DPM....it is used by a different
backup solution (Veeam) - the stand alone is visible in DPM but I have always had it as a disabled device. I have another DPM server in a separate data center with the same setup that doesn't have the issue. The only difference is that the second
DPM server DOESN'T have a second stand-alone tape drive connected. So I thought for a while that the stand-alone drive may have been the cause of this issue. I removed it completely....but the problem has not gone away.
Once the tape drive in the autoloader disappears a manual rescan is required and it will reappear and I can then use it again. It always disappears at time when it is in heavy use. We only perform tape backup tasks over the
weekends and this is always when the drive disappears, but it does not always disappear at the same time nor during the same job.   
I am still working to resolve this and I will be probably be raising a tech support case with MS shortly. So if I get an answer I will post back here.