Hi @Moshe Mazor 

As far as I know you must enable versioning and object lock when you create the bucket. Enabling it on an existing bucket is not supported. 
 

If you are creating the bucket, enable it and you can use Veeams object lock feature:

https://helpcenter.veeam.com/docs/backup/vsphere/immutability_capacity_tier.html?ver=110

Hi @Mildur 

Thank for the replay.
Look and the Migrating Data Between Different Buckets According to the following link https://helpcenter.veeam.com/docs/backup/vsphere/capacity_tier_migrating.html?ver=110

Veeam recommend enabling Versioning and the Object Lock features on the existing bucket instead of migrating data between buckets (If you need to migrate your data from a non-immutable bucket to an immutable one)

Or maybe I get it all wrong…

Thanks, wasn‘t aware that it works now.

Best to ask your object storage vendor if they support enabling the features on a existing bucket.

If yes, you can then activate capacity tier immutability and use it for new backups. Old backups will not be automatically immutable.

Thank @Mildur but, I really want to know what will happen to existent backup file on the capacity tier.
I have friend that enable it and the operation duplicate all of his backup files on the capacity tier...

I recommend to ask that question in the R&D forums.

I‘m not sure how veeam will react. Possible that each block (veeam doesn’t offload backup files, it offloads unique blocks to the capacity tier) must be offloaded again as an immutable block after enabling the features on a existing bucket.