I have same trouble like this (https://www-secure.symantec.com/connect/forums/bexec-125-puts-2nd-drive-offline-msl4048-after-extended-use). Try to change settings - don't help.
Try to run two job of backup. All start and both driver work and backups. Then after same time the second drive go to off-line. And it's delete from device manager (link in FC is off). Restart BE server - don't help. Restart tape library and then restart services (or server) - all go to on-line.
BE - 14.1798.1244. library expansion option.
Tape HP MSL 4048 - 8.60, M63W (FC). Connect directly to BE server via FC.
If you have a ProLiant server, stop the HP management agents. Check to see that the Symantec drivers are in use for the drives (you can use tapeinst.exe to do so) and then remove the Library Expansion Option (LEO) license and re-add it.
Then try a backup again.
Have you ran the HP Library and Tape Tool to check for hardware problems?
it is found at http://h20565.www2.hp.com/portal/site/hpsc/public/psi/swdHome/?cc=us&lang=en&sp4ts.oid=406731&ac.admitted=1395078039430.876444892.492883150
Yes, i have ProLiant server.
1. I stop all HP agents.
2. I use Symantec drivers for tape drive.
3. Remove LEO. Restart server. Install LEO.
Start backup. Both drive do backups and work fine about 2 houres and then 2nd drive go to offline :(
Strange, but 1 year all work fine (only two times that happend).
I think it's error in software, because it's not only my error, isn't it?
Any more idea?
...then I'd suggest following lmosla's advice about using HP LTT to test the library. You need to do the initialisation test which will check for any hardware issues, and then do a write test with both drives for which you'd need 2 x blank tapes.
I run HP Library and Tape Tool - LTO drive Assessmeте test (result in attachment).
The test has PASSED and the drive is GOOD (but was different in report in wrap and speed).
What else need to check?
Then after same time the second drive go to off-line. And it's delete from device manager (link in FC is off).
If the second drive is disappearing from Windows Device manager, then you have a hardware or a commincation problem, not a BE problem. If Windows cannot see the second tape drive, then BE cannot see it either.
Yes, but why it happend? If i don't run BE the FC still on-line.
And only when work backup on both driver this happend. If i backup only on first drive - all ok.
I try to change FC cabel - don't help.
In Windows event logs only one - A fibre channel HBA port has changed to a state of link down.
I allready update FC HBA firmware & drives, library and tape drive firmware, etc. - don't help.
But before all worked.