I made a video on the procedure, and the mandatory reading is:
A) upgrade guide
B) release notes
C) README from ISO for upgrade
Thoroughly review all the above docs and you'll have all the info that is required for the upgrade.
Videos are not available as YT disabled my account
Migration options are largely the same, no matter the versions involved, DRS, vMotion, PCD, copy the VM, etc.
In your case, PCD would do the job as it would remove the need to alter the VM specs, and change the disk size, and you'd end up with a fresh 12.x install.
No, for smart licensing you can allow direct registration, use a proxy, or use SSMS.
I'm still working on that, but I can't use any public video sites, I need to use internal alternatives.
Hi, I want to upgrade 9.1 to 12.0 is there any chance to see the video
Licensing is always handled separately, you need to have your smart account and virtual account ready as explained in the documentation, the video does not cover that. You either use the wizard from software.cisco.com if licenses are already there, or work with licensing to transfer your licenses (assuming you have your support contracts for major upgrades or bought the upgrade to be entitled to do so)
Licensing will depend on how your entitlement to use 12.x comes about. 9.x licences won't work for 12.x nor will they convert. If you have an active SWSS contract you can order the upgrade via PUT ("Product Upgrade Tool"). Cisco licensing will want to see the S/O from that upgrade order, along with your contract number and information from your 9.x ELM in order to issue your 12.x licences.