[pve-devel] [PATCH-SERIES storage/manager/guest-common/docs] improvements for protected backups

[Dominik Csapak]

On 12/21/21 16:11, Thomas Lamprecht wrote:
> On 20/12/2021 11:31, Dominik Csapak wrote:
>> what do we gain by having a limit on the number of protected backups?
> 
> We avoid allowing users to create an infinite number of backups.
> 
> Remember that unprotected backups do not count towards the keep-X retention
> parameters as they are considered a specially marked snapshot outside the
> regular schedule, and doing so could lead to situations where no new backup
> can be made (if sum of keep-X == sum of protected backups), which can be
> pretty bad.
> 
> Now, if a admin wants to limit the amount of backups a user can make of the
> VMs those users own, the admin sets now keep-X (which superseded max-backups)
> The sum of all keep-X is always the maximal, total amount of backups that can
> be made, but if the user marks every new backup immediately as protected they
> can overstep that limit arbitrarily, this series addresses that while not
> breaking backward comparability.
> 
>>
>> storage 2/2 mentions that protection broke some assumption of vzdump
>> which is (somehow? not really explained imho) fixing it?
>>
>> if it's not fixing it, what is the relation between those things?
>>
>> also, why have a 'magic' -1 value that means indefinite, we could
>> simply always have that behavior?
>>
>> in my opinion, it makes no sense to limit the number of protected
>> backups..
> 
> see above, having the whole picture should bring sense to this..
> 
>>
>> if it is necessary for some reason, it would be good to include
>> that reason either in the commit message, or at least in the cover
>> letter...
>>
> 
> I mean while the cover letter only hints it, commit message from the storage
> 2/2 patch is pretty clear to me.. FWIW, this was discussed quite extensively
> between Fabian E. and myself, and that result was further discussed with Fabian G.
> off-list.

OK, i get it now (also talked with fabian g. off-list).
i did not conclude from the storage 2/2 patch that
it implements an upper limit of backups, so i was confused.

Thanks :)