The method for doing this is to try and use the DATA COMPRESSION mode page
first, followed by the DEVICE CONFIGURATION page (this is because most newer
tape devices are now using DATA COMPRESSION instead of DEVICE CONFIGURATION
pages).
Add in the logical && hardware read position and set position ioctls. Oddly
enough, because NetBSD is limited in having the driver track file && record
numbers, the usual agony over what to do once you use logical or hardware
block positioning can be avoided. Amusing.
Make a minor change so that for SCSIVERBOSE cases that SCSI_SILENT in
the xs' flags is still observed.