[pbs-devel] [PATCH docs 1/3] docs: explain the working principle of the change detection modes

[Christian Ebner]

On 11/25/24 22:09, Thomas Lamprecht wrote:
> Am 18.11.24 um 10:24 schrieb Christian Ebner:
>> Describe in more details how the different change detection modes
>> operate and give insights into the inner workings, especially for the
>> more complex `metadata` mode, which involves lookahead caching and
>> padding calculation for reused payload chunks.
>>
>> Suggested-by: Dietmar Maurer <dietmar at proxmox.com>
>> Signed-off-by: Christian Ebner <c.ebner at proxmox.com>
> 
> it would be additionally good to describe why mtime, not ctime and when
> metadata detection can fail (if user/tools do bad things).

Agreed, will add more details on this as well.

> 
> And for the overview it would be great to note why a data mode exists, as
> there can be some confusions from users interpreting this as three different
> ways to create the archive(s), not two ways to do that with two change detection
> modes.
> Could be also interesting to note that it works with older PBS in general beside
> some archive specific features like file-browsing.
> 

Okay, will also add a short note that since the legacy mode and the two 
other modes use different archive formats, they do not reuse chunks as 
efficiently when using mixed modes on the same datastore.

> This mail is inspired a bit from the post I replied here:
> 
> https://forum.proxmox.com/threads/proxmox-ve-8-3-released.157793/page-2#post-723212