[Info-vax] BACKUP to the null device

[Michael Moroney]

helbig at astro.multiCLOTHESvax.de (Phillip Helbig---undress to reply) writes:

>Whu does BACKUP to NL:FOO.BAR give the error %BACKUP-F-INVDEVTYP but to 
>NL:FOO.BAR/SAVE_SET work?  If the error is correct in the first case, 
>why doesn't it apply in the second, since in both cases the target is a 
>file with the same device, directory, name, type and version?

That's because BACKUP would try to use the NULL device as a disk, 
directories and all, and directories don't make much sense on the null 
device.  Even in the simplest case (one file) it would want to make a
directory entry for the copied file.

In the second case, it creates a saveset as a simple file, and I think it
even uses RMS (except tapes).  It just throws data at a file.