no true incrementals with rsync?

Tony Abernethy tony at servacorp.com
Mon Jun 26 18:17:26 GMT 2006


(Flames invited if I've got this wrong or misleading;)

Traditional backup.  (call this DOS-style backup)
   Base: (full backup) (and turn all the archive bits off)
   Incremental: copy files with archive bit on (and turn them off)

Backup Files.  Add something (suffix) to indicate backup copies.
variations include suffixing (~) or changing extension to .bak or such.
It looks like --backup plays this game.
Everything in the same directory  (or a separate backup directory)

Call this one TRUE INCREMENTALS  (This works on UNIX-type system, not
DOS-type)
The key to the gizmo is that cp -l (or cp --link)
	does a real-fast copy by just copying hard links.
Each "TRUE INCREMENTAL" has its own target directory.
The rsync is (I think) a straight rsync (you do NOT want the --backup)
into a freshly prepared copy of the previous target.
The parameters to rsync need to be such that the anything that matters
is preserved on the OTHER copies of the files.
(When there are several files hard-linked, you need rsync to
unlink from the existing file and link to a newly-created file)
(instead of changing the contents of the file everything is linked to)
There are parameters to make rsync do EXACTLY what you want/need.
(I do not even pretend to know what they are or what they do)
(If everything is nice and simple, copy is nice and simple. If.)
(Rsync plays well in spaces where copy is (very) complicated)
(Just changing Permissions cause ...)
(If the changed file is very similar, ...)


> -----Original Message-----
> From: rsync-bounces+tony=servacorp.com at lists.samba.org
> [mailto:rsync-bounces+tony=servacorp.com at lists.samba.org]On Behalf Of
> tim594
> Sent: Monday, June 26, 2006 12:16 PM
> To: rsync at lists.samba.org
> Subject: no true incrementals with rsync?
>
>
>
> for example's sake:
>
> With traditional backup systems, you keep a base (full backup, let's say
> every 30 days), then build incrementals on top of that, eg. (what has
> changed since the base).
> So, to restore, you copy over your base, then copy each
> incremental over the
> base to rebuild up to the latest snapshot. (*copying new
> incrementals files
> over older base files*)
>
> With rsync, (using --backup, --backup-dir) it's opposite, you
> sync nightly,
> so your "base" is your most up to date, and your incrementals are
> files that
> have changed x days ago... EG. if you want to restore a snap shot from 5
> days ago, you copy over your base, then 1 days ago, 2 days ago,
> up to 5 days
> ago. (*copying older incrementals over newer base files*).
>
> am i right?
> Actually i think this method is better, because on a full uptodate restore
> you only need to copy over your base, as opposed to your base + all
> incrementals.
>
> THE QUESTION IS:
> anyone know a way to keep true incrementals including deletions?
> With rsync 2.6.6, when i use --delete or --del with the --backup command,
> the files it deletes are not backed up.  It would seem logical to me, if
> you're running the --backup command, all changes should be backed up,
> updates AND deletions.
>
> Thanks
>
> --
> View this message in context:
http://www.nabble.com/no-true-incrementals-with-rsync--t1850225.html#a505110
9
Sent from the Samba - rsync forum at Nabble.com.

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