[tahoe-dev] Potential use for personal backup

[Saint Germain]

On 22 May 2012 18:30, Shawn Willden <shawn at willden.org> wrote:
>> >> If I have a VM of 1 Go that I want to regularly backup on the remote
>> >> server. Do I get to use 1 Go on the home computer and 1 Go on the
>> >> remote computer for the current version and 1 Go for each backup of
>> >> the VM ?
>> >
>> > I don't understand what you mean by "1 Go".
>> >
>>
>> Giga-octets. Sorry 1 Gigabyte then.
>
>
> Interesting.  That's not an abbreviation I've seen.
>

It is often used in France but also sometimes to avoid ambiguous units:
http://en.wikipedia.org/wiki/Octet_%28computing%29

> Each file you back up is split into N pieces, each of 1/K size, and
> distributed to the servers in your grid.  So if you have a 1 GB VM on your
> desktop machine and you have two servers in your grid,  and K=1, N=2, Tahoe
> will split your VM into two pieces, each 1/1 = 1 x 1 GB in size and store
> one in each of your servers, for a total of 2 GB stored to back up the VM.
>
> Or for K=15, N=20, that would be 20 pieces, each 1/15 = .067 * 1 GB = 67 MB
> in size, for a total of 1.3 GB stored to back up the VM. :-)
>

Ok I get it.
However my initial intention was not to store the backup inside tahoe
filesystem (for diversification, for burning on a DVD, etc.).
The main idea was to have one big remote server storing the backup for
my whole family.
If I use tahoe backup, as soon as I trigger a backup on the remote
server, I will receive data on my home computer to also store the
backup (agree the amount is dependant on the number of nodes), which
is not really acceptable for my use case.

I guess that I'll have to use a mix of tahoe with bup.

Thanks !