You cannot upgrade to CUCM 15 using the backup from CUCM 14.
One option is to do a fresh install from data export, where you export the data from the old CUCM version by installing a cop file. Dat export copy the files to an SFTP server and when installing CUCM 15 we can import these data.
I suggest using PCD for migration, as it automates the process.
With FLEX you should get version agnostic licenses that can be used with any version. If you look in your Smart Licensing system do you see a version on the licenses in the list?
As @Nithin Eluvathingal wrote you cannot use a DRF backup from a different version to restore on another one. This has always been the case, so it’s not related to v15. Also I don’t think that you would need to upgrade to v14 first and then take the step to v15. Have you read the published upgrade documentation? It should contain the answers to most of your questions and if you still have additional questions please get back to your post.
@Roger Kallberg After reviewing the documentation, it is noted that Direct Refresh Upgrades from a pre-12.5.x source to Release 15 are not supported. The recommended approach is to initially upgrade your source to Release 12.5.x or 14, including any necessary Service Updates (SUs), and then proceed with the upgrade to Release 15.
Yes you must be on 12.5 or 14 if you want to upgrade to 15.
If you are 12.0 then upgrade to 12.5 or 14. Migration to 15 on a 15 OVA is what i will recommend which you do with PCD.
@Nithin Eluvathingal Do you have any recommendations for good documentation of PCD migration? I’ve never done one and we would likely be looking at doing this for our systems when we upgrade to v15 as there are a few constraints that pushes us in that direction based on the reading I’ve done so far.
As seen in your screenshot you can still do the PCD migration without first taking the extra step of upgrading to v14 and since you’re looking at getting from a 80GB disk installation to 110GB that’s likely the best option for you to select. With that you would not need to take the extra step of landing on v14. Also if you’re on 12.5 you can as well do an upgrade, the note mentions pre 12.5, ie anything below 12.5 not being supported. That said you’ll likely look at other constraints as you originally mentioned having 80GB disk installation, so all this is a pretty pointless discussion as either way you cannot do a direct upgrade. With that you’re best option would be to use the PCD migration option as stated before.
