BEXEC 14.0 puts 2nd drive offline in MSL4048
I have same trouble like this (https://www-secure.symantec.com/connect/forums/bex...). 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.