[Info-vax] BACKUP/BEFORE/BACKUP

[Paul Sture]

In article 
<639871e2-f144-4b9a-99ca-5561f605aa2a at y36g2000pra.googlegroups.com>,
 IanMiller <gxys at uk2.net> wrote:

> On Feb 8, 7:36 pm, hel... at astro.multiCLOTHESvax.de (Phillip Helbig---
> undress to reply) wrote:
> >      When you use /BACKUP with /BEFORE, files with a BACKUP date prior
> >      to the specified date or time are selected. Files with no BACKUP
> >      date (that is, /RECORD was not specified when the file was saved
> >      or copied) are also selected.
> >
> > That last sentence makes BACKUP behave differently than other commands,
> > and differently than BACKUP with other qualifiers.  Though this feature
> > is useful, why does it exist only in the combination above?
> 
> 
> I guess No backup date is same as 17 Nov 1858 so that is earlier than
> the specified date.

That is correct.  Another manifestation of zero = 17-NOV-1858 is the 
file retention date.  After setting a volume retention period for the 
first time on a given volume you really need to access every file on 
that volume to shift the retention date before DELETE /EXPIRED is safe.

BACKUP doesn't touch the retention date, so you need to do something 
like COPY every file on disk to NL: (any files which are locked _should_ 
have their retention dates adjusted by the application holding the lock, 
but it's probably safer to dismount and remount the volume after setting 
its retention period to be sure - if it's a system disk, then a reboot 
is called for).

-- 
Paul Sture