Incremental backups

[Karl Larsen]

On 05/18/2010 05:31 PM, Juan R. de Silva wrote:
> On Tue, 18 May 2010 11:04:52 -0400, H.S. wrote:
>
>    
>> Maxime Alarie wrote:
>>      
>>> Hi,
>>>
>>>
>>>
>>> I use Karmic 9.1 server, no UI!
>>>
>>> I have a server with about 40GB of important documents  on it.  I have
>>> setup a cronjob to backup a  filesystem  every night.. But now I would
>>> like to implement incremental backups every day. Because its starting
>>> to take too much space..
>>>
>>>
>>>
>>> The way I do it at the moment is  that I tar.gz the file system  and
>>> then I rsync to  sdb1. Once a week I rsync sdb1 with an external
>>> disk...
>>>
>>>
>>>
>>> I wondering if any of you know a good way to  setup incremental backups
>>> using nothing but the shell, since I have no UI on that server..
>>>
>>>
>>>
>>> Thanks.
>>>        
>> I have used the procedure described here to create a shell script (also
>> did this in perl and also in python) to create the scrips:
>> http://www.mikerubel.org/computers/rsync_snapshots/
>>
>> They are fairly easy to create once you read the link above. One of my
>> scripts does hourly backups and the other does daily backups. The most
>> important thing to consider is the directories or paths that you don't
>> to backup. For example, I exclude all .[Tt]rash*, .[Cc]ache*, tmp/, etc.
>> files and folders.
>>
>> I put these rolling snapshots and back ups on a different drive on my
>> computer (could be on the network as well). That drive is mounted a
>> read-only normally, but the scrips first remount it to read/write mode,
>> do their stuff, and reset it back to read-only mode, thus preventing any
>> accidental deletions.
>>
>> The advantage of using rsync and the way it handles hard links is that
>> numerous backups of the same data do not use negligible extra space.
>> Basically, only the changes take up the extra space. It is quite nifty
>> actually!
>>      
> I use the same system and I find it working flawlessly. Takes minimum of
> storage space and minimum time to make a next daily/weekly/monthly
> (whatever your preference is) snapshot.
>
> If you write your script that will run Rsync right way than it is easily
> customizable in terms of how many snapshots you want to keep, how often
> you want to make them. Basically the same script can be used to make
> either daily, and/or weekly, and/or monthly snapshots. (Unless you want
> you daily and weekly/monthly backup sets to be different but even then
> there is a minimum of customization involved). You only create different
> cron jobs.
>
> People do use rdif-backup and some other tools that actually utilize
> Rsync under the hood. They probably find them easier to learn, or to
> maintain. I'm not sure why...
>
> I personally find it more logical and actually easier to use Rsync
> directly instead.
>
>
>
>    
     Yes I wondered why you bother to gzip the entire software package 
and then use rsync to move the one file. You save moving billions of 
bytes by using rsync and make a backup of only changed files every hour 
and day.

73 Karl



-- 

	Karl F. Larsen, AKA K5DI
	Linux User
	#450462   http://counter.li.org.
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