Re: [BackupPC-users] Keep backup data when source host/directory changes

[Les M. <les...@gm...>]

On Wed, Mar 6, 2013 at 9:56 AM, Maarten <mt...@mi...> wrote:
>>>
>> Yes - the pool/cpool directory is full of extra hardlinks where the
>> hash of the content is the name to quickly match up new items (plus a
>> little extra work to deal with collisions).  Rsync just follows the
>> existing pc directory tree though, so you do have to copy the data
>> from each new location once, but storage is all pooled.  If the target
>> system is local, that usually isn't a problem.  If it is over a
>> low-bandwidth connection it might be worth some extra work to fake the
>> initial tree with a copy of the old link tree.
>
> OK, thanks for clarifying this. I feel silly that I have used BackupPC
> for years but never realized this.
>
> The bandwidth is not an issue, so I'm about to start a new full backup
> right away.

I'm not sure how much temp space will be required for the initial run.
 I think backuppc does something clever to handle matching small files
in memory to avoid any extra disk writes, but large ones may be saved
then subsequently replaced with links which might be a problem in an
extreme case.

-- 
   Les Mikesell
     les...@gm...