Re: Strategies for backup of millions of files...

On Tue, Oct 1, 2024, at 3:42 AM, Josip Deanovic via Bacula-users wrote:
> On 2024-10-01 03:16, Dan Langille wrote:
>> On Mon, Sep 30, 2024, at 10:48 AM, Marco Gaiarin wrote:
>>> Mandi! Dan Langille
>>>   In chel di` si favelave...
>>> 
>>>> From 
>>>> https://dan.langille.org/2023/12/24/backing-up-freebsd-with-bacula-via-zfs-snapshot/ 
>>>> :
>>> 
>>> I'm still doing some experimentation on this, indeed.
>>> 
>>> 
>>>> It doesn't all run as incrementals. If the list of DATASETS (see 
>>>> above URL) does not change, the fileset does not change.
>>> 
>>> OK, but if mountpoint change, so change root path, so... how can 
>>> bacula do
>>> incrementals, if all path are different?!
>>> 
>>> So.
>>> I can use script for the list of path to backup; i can use 'Ignore
>>> FileSet Changes = yes'
>>> (but if i use script i think it is not needed...) but how can bacula 
>>> do
>>> incrementals?
>> 
>> Bacula will just do it.  Nothing special required.
>
> This statement might be misleading in this particular case Marco
> described.
>
> Bacula will be able to run incremental backup but if the mountpoint is
> changing every time backup is running, the content of the mountpoint
> directory would be fully copied over and over again, thus, taking more
> space compared to the incremental backup of the same directory.
>
> As I said in some post, it might be avoided by using bind-mount option
> of the mount(8).

Now I understand the concern. Sorry for the misdirection.

The script in my blog post avoids that by using the same snapshot name every time it backs up:

See line 8: SNAPNAME="snapshot-for-backup"

The snapshot is created for this backup and deleted during the 'RunsWhen = After' script.

Hope that helps.

-- 
  Dan Langille
  [email protected]