Result after executing your statemet

Original Size of ServerAdmin LOG is 358648 8K pages or 2801MB

Cannot shrink log file 2 (ServerAdmin_Log) because the logical log file located at the end of the file is in use.

DBCC execution completed. If DBCC printed error messages, contact your system administrator.

Msg 155, Level 15, State 1, Line 1

'TRUNCATE_ONLY' is not a recognized BACKUP option.Minimum Quantity : 50000

Maximum Time : 5 minutes (300 seconds)

Final Size of ServerAdmin LOG is 330112 8K pages or 2579MB