Re: File Formats

On 27/03/2021 07:29, [email protected] wrote:
> On 25.03.2021 09:29, [email protected] wrote:
>>> I just heard about rdiff-backup and I'm planning how to
>> configure it.
>>> The documentation says:
>>> "Earlier states of your files are saved just by 1) keeping
>> a copy of
>>> them,
>>> 2) in diff form as produced by rdiff, or 3) as a gzipped
>> version of 1 or 2."
>>> I see the --no-compression option to disable compression.
>> However I do
>>> not see an option to produce copies of older files vs.
>> storing them in
>>> rdiff format. How is the file format for older files controlled?
>>>
>>> Thanks much!
>> Hello and welcome!
>>
>> I don't think it matters to you - it should be just a
>> description of how rdiff-backup handles file history internally.
>>
>> --no-compression should disable compression of older files
>> when a newer snapshot is created. It's sometimes useful to
>> disable compression because gzip is rather CPU hungry and
>> depending on files it can make the backup take a long time.

> Actually it does matter to me. I do not want to rely on a chain of reverse
> diffs to reconstruct important files. My concern is that a disk error could
> render reconstruction impossible. I would like every version to remain as a
> self-contained snapshot. So, I want to use compression and snapshots only.
>
> The documentation says that earlier states of files can be saved as copies
> or diffs. However there does not appear to be a run-time option to create
> copies. I looked at the python code in increment.py and it does not seem to
> have an option to create copies for regular files.
>
> Is there a way to force rdiff-backup to always create copies of earlier file
> versions?
You can verify rdiff-backup repositories as a way to give you 
confidence. My approach to guard against disk error is to take a 
straightforward (rsync) backup of my rdiff-backup repositories but only 
after they are verified.

But if you insist on atomic backups-in-time then maybe something like 
rsnapshot would be a better tool for you.

BTW the style here is to bottom-post.