[Discuss] On-site backups revisited - rsnapshot vs. CrashPlan

[gaf at blu.org (Jerry Feldman)]

On 02/21/2013 09:53 AM, Derek Atkins wrote:
> Jerry Feldman <gaf at blu.org> writes:
>
> [snip]
>> Also, rsnapshot has a decent logging mechanism. Unfortunately, rsnapshot
>> assumes a Unix/Linux file system (hence hard links), so you really could
>> not use it to back up a Windows file system in the same way.
> I don't understand this last statement.  While I understand that you
> couldn't backup *to* a windows file system, I don't understand why you
> cannot backup a windows file system?
>
>
You certainly can use it to back up a Windows file system. The reason
why I made the statement is that with rsnapshot or any backup system
that uses the --link-dest feature of rsync, you are not going to have
the benefits of hard links. When you back up a file system, you want to
retain the attributes. The Linux file attributes are the Unix permission
scheme and ownership. The Windows attributes are Archive Hidden, System,
and Read-Only. With a Linux file system, you are backing up the entire
directory tree. So, you have your hourlies, dailies, et. al. as complete
directory trees with the changed files breaking the hard link, but the
same files sharing the same hard link. You certainly could back up a
Windows directory tree in the same way you back up a Linux directory
tree, but on Linux you will lose the Windows attributes. The beauty of
rsnapshot and other Linux backup systems that use rsync is that the
incremental backup is a full directory tree. So, you don't have to
manage things like full backups and incrementals. Every backup is both
an incremental and full backup. Additionally, with rsnapshot (and other
rsync based systems) your backup is a full Linux file system, not a
database.

btrfs certainly has a number of excellent features built-in, but I
prefer a complete backup of my /home /etc and a few other directories. I
doubt I will ever need a file from 3 months ago, but the additional
space is minimal.

-- 
Jerry Feldman <gaf at blu.org>
Boston Linux and Unix
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