Re: [Tails-ux] Clone Persistence option in Tails Installer (…

Hi,

intrigeri:
> sajolida:
>> intrigeri:
>>> sajolida:>>>> - Is it fine to copy the content of the current Persistence while it is
>>>> being used?
>>>
>>> Doing so creates inconsistent backups: among a set of files that are
>>> supposed to go together (be it config, program data, user data), some
>>> of them are backup'ed at version N while some others at version N+1.
>>>
>>> Inconsistent backups ⇒ inconsistent data sets. That can break
>>> software's ability to use the data at various degrees. I can't tell
>>> off-hand how bad this can be but it has the potential to make software
>>> with large and complex data store, such as Thunderbird,
>>> really unhappy.
>
>> Understood. Then we should prevent users from updating their backups
>> while the problematic applications are open.
>
> Yep.

Note that we need the same functionality for #11529.

>> I assumed that working on the block device level would mean copying the
>> whole Persistence partition block by block every time. Doing a dd of
>> Tails (1.2 GB) to a USB stick takes around 5 minutes, so doing full copy
>> of a 5.5 Persistence would take around 30 minutes. Not fast. Especially
>> if you can't use Thunderbird while your backups are updating.
>
> That's of course a no-go.

I think doing a full dd copy is a no-go anyway, because it just takes
too long. Users might also have a lot bigger persistence partitions. IMO
we should use the filesystem both to create and update the backup.

Cheers