[plug] OS X -> Linux Backup

Timothy White weirdit at gmail.com
Thu May 11 10:14:32 WST 2006


Ok, finally decided to bring this to the list.
Basically, I'm looking at setting up a backup system, that
automagically backs machines up over the network, via rsync. Oh, and
it's a Linux server, and OS X clients ;-)

So the big question is, resource forks, and Extended Attributes.
Now I'm fairly sure EA's are easy, and rsync will handle them, as long
as my filesystem supports them, so as long as I use XFS, or reiserfs
or ext3 with EA's enabled, I'll be fine.
So the problem is Resource Forks. I know HFS+ supports them, and UFS
doesn't, and  I believe OS X stores them as . files (.DS_Store I think
is one example) on UFS, and other file systems that don't support the
forks. I know the machines I'm backing up are all going to be HFS,
which means firstly I need a version of rsync that supports resource
forks, and a filesystem that also supports them.

What do other people do in this instance? Do you even care about the
forks? Somewhere I read it, it was only Finder info, and Carbon apps
that needed them. I'm sure /someone/ on this list has faced this
problem before, of having to backup OS X machines ;-)

Lastly, what recommendations do people have about rsync based backups.
I've seen rsnapshot, which uses hard links, and rotating backups. But
I discovered the flaw, that for example, if you create a file on
Tuesday, delete it on Wednesday, while it has made it into the daily
backup for Tuesday, it will not make it into the weekly backup, so you
have until next Tuesday to recover it. [1]
Another one I'm looking at is rsync-diff. I've not yet tried it, so
can't comment.

What methods do people use to do incremental 'full' backups? A number
of the machines getting backed up are laptop's as well, how do you
handle this, do you try and do a backup as soon as it's plugged in?
How do you handle backups that don't get to finish? I don't wish to do
tar.gz style backups, cause all the other methods (snapshot style,
using hardlinks, or complete image of latest version, with diffs in
special folders) allow for easy browsing of at least the latest
backup, and easy recovery of files.[2]

Tim

[1] If I was to use rsnapshot, I would set it up to do a month worth
of daily's, or something similar.
[2] I like rsnapshot's ability to provide the user with a 'complete'
image for each backup. But don't like how it rotates the backups. I
like rsync-diff for doing a single image, and diff's, but that doesn't
make it as easy to restore older versions of the file.
-- 
Linux Counter user #273956



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