Hello @PatricG 

No, upgrading the OS does not consume an extra license and it does not affect Capacity License. Capacity is calculated based on the last Full backup of each subclient.

Capacity-Based Total License Usage - https://documentation.commvault.com/2023e/essential/capacity_based_total_license_usage.html

In capacity-based total license usage, usage is calculated by taking the largest data protection job for a client during the time period (one month), regardless of whether the client is still actively used at the end on of the billing period. This means that out of all jobs for a given client, the software uses the largest full backup job or synthetic full backup job for that month as the total. The size of the largest job is used to reflect the usage for that client for the entire month, even if the client is removed before the end of the month. The sum of all of the largest jobs for all unique clients is the total usage billed.

Thank you,

Collin

Hi @PatricG ,

As advised by my colleague @Collin Harper , upgrading the OS won't consume any additional licensing as long as the same iDA is backing up the machine under the same Client Machine within the CS. It will calculate capacity based on the largest backup job regardless of the OS used by the Client.