How to fix the Oracle error ORA-09851: soacon: Archmon unable to lock named pipe.?

In this post, you’ll learn more about the Oracle ErrorORA-09851: soacon: Archmon unable to lock named pipe. with the details on why you receive this error and the possible solution to fix it.

Oracle Error Description

ORA-09851: soacon: Archmon unable to lock named pipe.

Reason for the Error ORA-09851: soacon: Archmon unable to lock named pipe.

fcntl() failed to set read lock on named pipe ?/dbs/mon2arch_@.

How to fix the Error ORA-09851: soacon: Archmon unable to lock named pipe. ?

You can fix this error in Oracle by following the below steps

Make sure that archmon is not already active on another terminal for this ORACLE_SID. Only one archmon session is allowed at a time for a given instance.