Hi i have 2 cisco ASA 5550 in Active/standby.
I want to upgrade anyconnect license to 5000 users, Do i need to buy two license one for each ASA, or i can go with only one for the active ASA ????
When you perform the upgrade, it will automatically convert your 8.2 configuration to 8.4 configuration.
8.4 has the same configuration as 8.3, so you can refer to the same document to upgrade from 8.2 to 8.3.
Here is the documentation that list down the changes in version 8.3 and later (inc. the old config and the new config):
If you're depending on these devices for 5000 remote users I would hope that you have Smartnet support and thus be eligible to upgrade.
I'd definitely recommend upgrading to 8.4 and then applying your single new license to be shared between the HA pair.