[Info-vax] VMS version numbers, was: Re: DCL enhancements
Jiří Kašpar
kaspaji3 at fit.cvut.cz
Thu Jan 28 05:42:16 EST 2021
Shuffling when ;32767 is reached can be late.
We need a new file attribute to start autopurge:
$ SET FILE x.y/SHUFFLE_LIMIT=n
When version reaches the limit, shuffle autopurge starts asynchronously and application should be able to continue run and create new file versions over the limit.
There is a question if there shoudn't be more general mechanism for triggering file events:
$ SET FILE x.y/TRIGGER=event/ACTION=procedure
Or maybe better to define/store it in ACL.
But this can be security issue.
On Wednesday, January 27, 2021 at 7:45:17 PM UTC+1, Phillip Helbig (undress to reply) wrote:
> In article <rusbmg$sn5$1... at dont-email.me>, Simon Clubley
> <clubley at remove_me.eisner.decus.org-Earth.UFP> writes:
>
> > On 2021-01-27, VAXman- @SendSpamHere.ORG <VAX... at SendSpamHere.ORG> wrote:
> > > In article <388edf53-8ba9-4f66... at googlegroups.com>, Jon Pinkley <jon.p... at gmail.com> writes:
> > >>
> > >>And setting the version to one is really an autopurge, it still creates new
> > >>version numbers that will eventually get to ;32767 and then possibly cause
> > >>problems. The point is ODS is not NTFS or some unix/linux versionless file
> > >>system. And there are many vms applications that rely on versions.
> > >
> > > Purge and rename them back to start at ;1.
> >
> > Which still gives you application failures if you don't catch it in
> > time and application downtime while you apply this fix.
> >
> > I wonder how much effort would be involved in adding support to VMS
> > to automatically shuffle down the existing file versions when something
> > tries to create a new version after ;32767 is reached on a file ?
> Be careful what you wish for. It is bad enough reaching ;32767.
> Imagine a runaway application. With ;32767, at least it stops. With
> reshuffling, it won't, and there will be the overhead of reshuffling.
> > BTW, does anyone know how versions will be handled on the new filesystem ?
> >
> > Will versions still be supported and if so, will they still be 16-bit
> > version numbers or will they be increased to at least 32-bits ?
> I really don't think anyone needs 32 bits here.
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