Hi,
> > The documentation mentions exponential expiring incremental backups
> > (http://backuppc.sourceforge.net/faq/BackupPC.html#backup_basics):
> > "BackupPC can also be configured to keep a certain number of
> > incremental backups, and to keep a smaller number of very
> > old incremental backups."
>
> while I don't really understand what "keep a smaller number
> of very old incremental backups" is supposed to mean, there
> is no mention of exponential incremental backup expiry.
In the past we've used programs like snapback to do only once a full backup
and subsequently just store the differences. This approach has several
limitations and that's why we are looking into alternatives. (Disclaimer: I
don't want to start (yet another) discussion about the pro/cons). But for us
a total file storage size with a couple of TB a full backup takes a few
days. Therefore we can't easily afford running a full backup every 1 or 2
weeks.
Just finding all relevant parameters for Incremental and Full backups named
the same (Period, KeepCnt, KeepCntMin, AgeMax) and reading "Exponential
expiry [for full backups] is specified using an array for FullKeepCnt" lead
me to the question if this is also true for IncrKeepCnt.
In this context I've interpreted the documentation "keep a smaller number of
very old incremental backups" as an "exponential incremental backup expiry".
> > Are "exponential expiring incremental backups" supported?
> [...]
>
> Why would you want that?
>
> Incremental backups are there for gaining a speed advantage -
> an advantage that will allow you to make daily (or hourly or
> whatever) backups.
You've said it. I was interested in the speedup (and I know e.g.
http://www.mail-archive.com/backuppc-users AT lists.sourceforge DOT
net/msg04341.ht
ml)
> (*) Actually, you probably need regular full backups with any
> backup scheme.
> It's just that on this list, we make a point of telling you ;-).
Sometimes it is tough to tell the truth :-) And I understand the technical
explanations why you mention this. So would classify this page
(http://en.wikipedia.org/wiki/Differential_backup#Synthetic_full_backup) as
"needs improvement"?
Thanks!
christian
------------------------------------------------------------------------------
Come build with us! The BlackBerry® Developer Conference in SF, CA
is the only developer event you need to attend this year. Jumpstart your
developing skills, take BlackBerry mobile applications to market and stay
ahead of the curve. Join us from November 9-12, 2009. Register now!
http://p.sf.net/sfu/devconf
_______________________________________________
BackupPC-users mailing list
BackupPC-users AT lists.sourceforge DOT net
List: https://lists.sourceforge.net/lists/listinfo/backuppc-users
Wiki: http://backuppc.wiki.sourceforge.net
Project: http://backuppc.sourceforge.net/
|
