Sometimes when troubleshooting backups I want to see if the host can drive data to a tape drive at high speed without involving a filesystem or backup software or the like.
I've got some slow NDMP backups on some filers that have fiber-attached LTO-3 drives.
At the moment I'm assuming that the contents of the filesystem make it difficult to drive the tapes at high speed, but it would be nice to have another data point that would show that the local drive is or is not behaving properly.
Is there any way to have the filer send data to the drive without actually invoking an NDMP backup or running a 'dump'? On another host I might mount a scratch tape and run 'dd if=/dev/zero of=/dev/tape' with an appropriate block size and count.
I see a 'dd', but I don't know of a data source like /dev/zero. Is this or something similar possible?
Thanks.