Re: n00b questions about using dar for archiving wikis [apologies]

the man page is more a reference document (all details, on all) you
probably won't have to read it sequentially as a whole.

Tutorial and FAQ are better for startup, For a particular feature you
can then jump to the man pages and you can also ask questions here about
things that would not be clear to you, give feedback if some text in
unclear or lacks example as illustration, and so on.

Cheers,
Denis

On 24/07/2021 09:28, griffin tucker wrote:
> thanks. i'll read the man page, but it will take me a while (it's long).
> 
> it looks as though i'll be doing a differential backup, but we'll see.
> if i can't backup one file to a backup at a time, then i'll have to
> invest in more storage, which will take some time to save up for.>
> On Sat, 24 Jul 2021 at 03:33, Denis Corbin <[email protected]> wrote:
>>
>> On 23/07/2021 08:43, griffin tucker wrote:
>>> i didn't mean to upset you, i don't want you to do any development
>>> unnecessarily.
>>
>> no worries, I just had not time to answer you, having a quite busy week
>> at work, sorry for that.
>>
>> In brief, if you want to add new files to an already existing and
>> completed backup, you cannot do that with dar (you can with tar but have
>> to disable several other features, like compression and multi-volume
>> AFAIR). With dar, you rather make a differential backup, or another full
>> backup and convert the previous full backup to a decremental one.
>>
>> There is no plan to have such feature with dar as it would ruin the rule
>> followed by dar to never modify an existing backup, but create a new one
>> beside the old ones (while repairing, merging, and other operations)
>> leaving the decision to the user to remove *or not* the old backup
>> keeping them, for example, as secondary backups.
>>
>> As explained in a previous email, the binary delta feature (that makes a
>> rsync like increment) is not available with decremental backup today.
>> Without this feature, when a file's data changes the whole file is saved
>> again (and is eventually compressed in the backup depending on your
>> choice). Technically having binary delta with decremental could be
>> possible, but so far the need did not seemed very strong for that.
>>
>>
>> If you don't know whether dar is the tool that matches you need, check
>> the documentation like the tutorial, it's always better to validate by
>> yourself as you know better than anyone here the goal you tend to address.
>>
>> tutorial: http://dar.linux.free.fr/doc/Tutorial.html
>>
>> Feel free to ask if you have any particular question on how works or how
>> to use any particular dar/libdar feature.
>>
>> Cheers,
>> Denis
>>
> 
>