Changing from Standard to Advanced Security Might Require Manual Removal of Remote Service Accounts
If remote site systems are online when you change the security mode from standard to advanced security, the remote SMS service accounts on those site systems are automatically deleted, and the Local System account is used. However, if the remote site systems are offline when you change the security mode, the Local System account is still used, but the remote SMS service accounts on those site servers are not automatically deleted.
WORKAROUND: Delete the remote service accounts manually after you change to advanced security.
SMS Might Become Backlogged When SMS Site Database Runs Out of Free Disk Space
When upgrading from SMS 2.0, the SMS site database will increase in size due to the modified software inventory and software metering schema and tables.
WORKAROUND: Ensure that adequate free disk space is available to allow the SMS site database to double in size after upgrade as the site continues to process updated inventory.