On Sun, 20 Jun 2010 19:41:34 -0400, Mike Kallies <mike.kall...@gmail.com>
wrote:
> Hello Everyone,
>
> I've been using BackupPC in production and at home enviornments for the
> past couple years. It's a great program, but I'll add that it takes a
> while to get the hang of how it does things.
>
> So here's my question. Is it necessary to take a full backup at a
> regular interval? I mean, can't BackupPC fill-in the incrementals to
> simulate a "full" then do a superficial compare of the backup directory
> tree against the client's directory tree (e.g., compare the
> date/time/size/attributes)? Sort of "flattening" an incremental?
>
> I want to do this because I'm currently setting up BackupPC to use rsync
> to keep backups of hosted website. By default, my backup policy is
> going to take a "full" backup every week. This is going to transfer 1GB
> of data every week... that's not ideal. The web host isn't going to
> like me, and it shouldn't be necessary for me to transfer that much
data.
Ah - when using 'rsync' or 'rsyncd' as the transport, backuppc has a
slightly different notion of what a "full" backup is than other backup
software.
When using rsync, only the block differences are EVER sent across the wire
(unless you add '--whole-files' to the cmdline, IIRC). In backuppc, the
only difference between a full and an incremental is how rsync determines
what data to send. In an incremental, files are checked via last-modified
time; in a full backups, a block-level compare is done across all files.
This means the only real performance hit on a full backup is that the
client rsync must read every block of every file -- but no extra data is
sent across the wire.
-Josh
--
--------------------------------------------------------
Joshua Malone Systems Administrator
(jmal...@nrao.edu) NRAO Charlottesville
434-296-0263 www.cv.nrao.edu
434-249-5699 (mobile)
BOFH excuse #415:
Maintenance window broken
--------------------------------------------------------
------------------------------------------------------------------------------
ThinkGeek and WIRED's GeekDad team up for the Ultimate
GeekDad Father's Day Giveaway. ONE MASSIVE PRIZE to the
lucky parental unit. See the prize list and enter to win:
http://p.sf.net/sfu/thinkgeek-promo
_______________________________________________
BackupPC-users mailing list
BackupPC-users@lists.sourceforge.net
List: https://lists.sourceforge.net/lists/listinfo/backuppc-users
Wiki: http://backuppc.wiki.sourceforge.net
Project: http://backuppc.sourceforge.net/
