[Info-vax] strange backup behavior

[Bob Koehler]

In article <f3e89c46-2e8d-4c1c-bf0b-11124e349984 at k13g2000prh.googlegroups.com>, B Hobbs <bdhobbs18 at acm.org> writes:
> 
> I'm wondering if the emulator's TK50 tape driver is interacting poorly
> with BACKUP and the SDLT drive.  Ideally, someone with a real VAX, an
> HP SDLT, and VMS 7.1 could BACKUP a short file to an empty tape
> cartridge, BACKUP several tens of gigabytes of data to the tape, then
> BACKUP the same short file to tape, all with timing info.  If their
> test shows the time for the third BACKUP to be close to the first
> BACKUP, then my emulator becomes the prime suspect.

   I'm really starting to suspect the emulation.  I wonder if the
   emulation writer had UNIX in mind, where the default device rewinds
   the tape every time you close the file on the tape.

   OBTW, you're not running the emulation on UNIX, are you?  If so,
   maybe you can tell the emulator to use the no-rewind interface.