Re: update anonftpsync
On Thu, Feb 28, 2008 at 07:43:13PM +0100, Arnt Karlsen wrote:
> On Tue, 26 Feb 2008 14:46:11 +0100, Josip wrote in message
> <[🔎] 20080226134611.GA25476@keid.carnet.hr>:
>
> > On Thu, Feb 21, 2008 at 11:01:34AM -0500, Justin Pryzby wrote:
> >
> > > --delay-updates --delete-after
> > > I don't know if either of these are strictly necessary. AFAICT
> > > think the 2nd rsync invocation can just use --del.
> >
> > --delay-updates helps the atomicity of updates, see the manual.
I was thinking it was an solution for a nonextant problem. I think I
was wrong though, since the Release and Packages files are supposed to
be in sync, which AIUI can never be pefectly solved but just minimized.
I don't know if there are any relationships besides "Packages depends on
debs" and "Release depends on Packages", though.
> > --delete-after is necessary so that it doesn't first delete files and
> > then bring in new ones.
--del does that, but per file.
> ..one argument in favor of --del alias --delete-during, AFAIUI,
> is --delete-after is quite hard on mirror disk space.
>
> ..will --del toss away each old .deb etc immediately _after_
> each new one .deb is in, or immediately _before_?
I think that's asking the wrong question. The content for a a given
.deb filename is never changed (that's Debian archive convention). It
can just be removed. The 2 pass rsync makes sure that all the new debs
(referenced by the new Packages file) are in place before sending the
new Package file itself (to avoid referencing not-yet sent files). The
2nd rsync (sending everything but the already-sent .debs) with --del
will remove the .debs that don't exist on the sending side, which are
(supposed to be) guaranteed to be no longer referenced by the Packages
files.
Justin
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