What is a driver, device file, device path in netbackup

There are two paths to the drives in Unix/ Linux

Solaris for example ...

/dev/rmt/0cbn - the OS device path

/dev/st/xx - the pass thru path

Some scsi commands commands eg. rewind / fast forward can be sent via the device (os) path, pretty much the same as the unix mt commands (mt -f /dev/rmt/0cbn rew to rewind a tape for example).

Other scsi commands, such as 'test unit ready' used when mounting a tape, to discover when thedrive has got things sorted and is ready to read/ write cannot be sent via the os path, and therefore go via the sg, or pass thru path.

So sg issues, in solaris can be our fault.

In linux, the pass thru oath (also known as sg) belongs to the os, so pass thru issues are usually down the the os vendor to sort out.

Generally, the only pass thru issue you see these days are on solaris, and in 99.9% of cases, is fixed by rebuilding them.   Usually, new drives don't appear in scan / tpautoconf (these scsi commands go via the sg driver ) and is simply a config issue.

In fact, in 8 years, I don't remember a single time an sg issue has been anything other than a reconfig to fix.