Check out this post in the community from v11 but still related to v12 for CDP retention - https://community.veeam.com/blogs-and-podcasts-57/vbr-v11-how-cdp-works-with-retention-policies-628#:~:text=Veeam%20Backup%20%26%20Replication%20retains%20short-term%20restore%20points,for%20a%20VM%20replica%20with%20one%20virtual%20disk.

It has links to short and long term explanations.

@Chris.Childerhose I have read the post, but it doesn’t explain how to size my Destination Datastore capacity and what calculator that i can use for CDP Policy

For CDP retention is based on VMDK sizing of the VMs you are protecting.  Remember CDP uses snapshot based technology for the replication.  For calculating I am trying to find something on the Veeam calculator site but not seeing anything.

HI @dika - there is no “official” Veeam retention Calculator for CDP that I could find, as Chris also shares. But, one of the Product Managers in the Forums shared in this post on how to try to size your CDP Datastore. Main thing needed to calculate your DS capacity is change rate per period and retention period.

Hope that helps.

The link shared by Shane is probably the only thing I remember about CDP calculations. 

It’s on my list to test out some CDP sizing options and publish a blog post about this, but I haven’t had a chance to do so.  I’ve managed to fill my datastore a few times with CDP replica’s so suffice it to say, my recommendation is to start out slow and work your way up monitoring your datastore usage.  You can try and calculate the amount of space needed, but it requires you to know things like Change rate as well which can be a bit harder to determine, so I’ve just had to work my way up, or rather, I had to work my way back from trying to use too much space (I recommend doing better than I have though).  I’m preparing to deploy a new SAN however, and I think what I’m going to do is create a datastore for snapshot replica’s and a second datastore for CDP replica’s so at least if the three VM’s I’m using CDP for grow too much, it won’t affect anything else.

Hi @dika -

I’m just following up on your CDP sizing post to see if any of the provided comments helped answer your question? If so, we ask you to please select which one did as ‘Best Answer’ so others who come across your post with a similar question may benefit.

Thank you.