Issue:
While running the RMAN backup command getting the following error,
cannot make a snapshot control file
released channel: c1
released channel: c2
released channel: c3
released channel: c4
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03009: failure of backup command on c1 channel at 02/28/2020 20:15:58
ORA-00230: operation disallowed: snapshot control file enqueue unavailable
RMAN> Recovery Manager complete.
(or)
RMAN backup log file shows below while running
waiting for snapshot control file enqueue
waiting for snapshot control file enqueue
waiting for snapshot control file enqueue
waiting for snapshot control file enqueue
waiting for snapshot control file enqueue
Solution:
Check any other RMAN backup process running in server level and kill the os process
$ ps -ef|grep rman
$ kill -9 pid
after killing the OS process also getting same snapshot error. Please follow the below,
Execute the following query to determine which job is causing the wait:
SELECT s.SID, USERNAME AS "User", PROGRAM, MODULE,
ACTION, LOGON_TIME "Logon", l.*
FROM V$SESSION s, V$ENQUEUE_LOCK l
WHERE l.SID = s.SID
AND l.TYPE = 'CF'
AND l.ID1 = 0
AND l.ID2 = 2;
You should see output similar to the following (the output in this example has been truncated):
SID User Program Module Action Logon
--- ---- -------------------- ------------------------- ---------------- ---------
785 SYS rman@exad (TNS V1-V3) backup full datafile: ch5 0000007 STARTED 24-OCT-16
SQL> select sid,serial#,username,osuser,machine,event,program,sql_id,blocking_session,logon_time from gv$session where status like 'ACTIVE' and SID='785';
ALTER SYSTEM KILL SESSION '785,37463' IMMEDIATE;