[Info-vax] BACKUP to the null device

[AEF]

On Feb 8, 4:41 pm, moro... at world.std.spaamtrap.com (Michael Moroney)
wrote:
> hel... 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.

But what fails with BACKUP works fine with COPY:

DCL> COPY LOGIN.COM NL:
%COPY-S-COPIED, DISK$DATA1:[FELDMAN]LOGIN.COM;85 copied to NL: (14
records)
DCL> COPY LOGIN.COM NL:[ASDF]
%COPY-S-COPIED, DISK$DATA1:[FELDMAN]LOGIN.COM;85 copied to NL: (14
records)
DCL> COPY LOGIN.COM NL:[ASDF]ZXCV
%COPY-S-COPIED, DISK$DATA1:[FELDMAN]LOGIN.COM;85 copied to NL: (14
records)
DCL> COPY LOGIN.COM NL:[ASDF]ZXCV.1234
%COPY-S-COPIED, DISK$DATA1:[FELDMAN]LOGIN.COM;85 copied to NL: (14
records)
DCL> COPY LOGIN.COM NL:[ASDF]ZXCV.1234;90
%COPY-S-COPIED, DISK$DATA1:[FELDMAN]LOGIN.COM;85 copied to NL: (14
records)
DCL> COPY LOGIN.COM NL:[ASDF]ZXCV.1234;90
%COPY-S-COPIED, DISK$DATA1:[FELDMAN]LOGIN.COM;85 copied to NL: (14
records)
DCL>

AEF