continuous backup solution for FreeBSD

[Zaphod Beeblebrox]

On Wed, Oct 8, 2008 at 2:01 PM, Evren Yurtesen <yurtesen at ispro.net> wrote:

> Zaphod Beeblebrox wrote:
>
>>
>> Wow... thanks for the flame, but there's no reason that the  device that
>> is receiving the hammer replication couldn't be on the other side of the
>> globe and there's no reason it couldn't be considered a backup.  Part of the
>> advantage of the structure that allows you to efficiently select for new
>> changes allows you to do the same kind of *backup* as they claim.
>>
>>
> Wouldnt that device need to keep the whole filesystem? Like if you have 10
> machines with 10x 1GB drives (lets say each used about 250gb), you will need
> 10TB disk space in the backup server?
>


Urm... I think everything we've been discussing here backs up the whole
filesystem (it would be near impossible for a block-oriented system to do
elsewise).  I suppose you could do something with the archive bit or dump
bits with a filesystem based backup.

But anyways... in a filesystem based replication system, you'd need enough
space to store the data and the history of the data.  The sum of the history
of the data could even exceed the size of the sum of the input disks.  It
could also be much smaller.  It really depends on how much you change.