On 15/06/10 14:31, Tom Furie wrote:
On Tue, Jun 15, 2010 at 01:02:47PM +0100, Alan Chandler wrote:
On 15/06/10 12:44, Alan Chandler wrote:
The real magic command is "cp -alf" which essentially merges a shorter
term store with a longer term one, making new entries where the shorter
store has a file that isn't in the longer term store, and overwriting it
where the shorter term store has a file with the same name as the longer
one.
I should have added, it does this virtually instantaneously because it
is not moving anything, just dealing with hard links.
Links are no way to handle back-ups. If the data goes bad, that just
means there's multiple places you can't get at it from.
You misunderstand me. Links are not used to avoid having two copies of
everything, but just a way to merge either a daily snapshot into a
weekly one, or a weekly snapshot into a monthly one. The magic is that
it does it almost instantenously.
My thought process was about how many backup copies do I need of
something that changes daily - like a database (and its backup dump).
I keep a separate version of the file for every day for a week. I then
keep a single version for each week the following 5 weeks and then turn
it into one version every month for 6 months - and from there is sits in
a queue for archiving to dvd.
This allows me to go back in time. Say I screwed up and corrupted data
and didn't notice for a month. The best I can do is get a backup around
a week of that occurrence not one of the daily ones. If I didn't notice
for 6 weeks, then I would only have a monthly snapshot to choose from.
--
Alan Chandler
http://www.chandlerfamily.org.uk
--
To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org
with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org
Archive: http://lists.debian.org/4c193950.8080...@chandlerfamily.org.uk
