ADR file lock wait event during RMAN L0 And L1 Backup

I will explain ADR file lock wait event during RMAN L0 And L1 Backup in this post.

Rman Level 0 takes long time and does not complete.

Even L1 Backups end up in the same state

At the  time when the rman backup seems to hang following error is reported in the database alert log.

Incremental checkpoint up to RBA [0x9c6e.11752.0], current log tail at RBA [0x9c6e.124dc.0]
Sun Jun 09 02:42:39 2019
Errors in file <path>/<SID>/trace/<SID>_ora_10225.trc:
ORA-48132: requested file lock is busy, [HM_RUN] [<path>/lck/AM_1618_3044626670.lck]
ORA-48170: unable to lock file - already in use
SVR4 Error: 11: Resource temporarily unavailable
Additional information: 8
Additional information: 10759
Sun Jun 09 02:56:30 2019
Incremental checkpoint up to RBA [0x9c6e.148ff.0], current log tail at RBA [0x9c6e.15967.0]



INST_ID SID CH SEQ# EVENT STATE SECONDS
---------- ---------- -------------------- ---------- ---------------------------------------- ------------------- ----------
2 4052 rman channel=ch06 20780 ADR file lock WAITING .43                                                                       >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

...

2 1649 rman channel=ch12 14041 ADR file lock WAITING 2.30

RMAN backup was taking time due to ADR file lock wait event.

Similar issue was reported in Below bug but closed as not a Bug

Bug 10125939 – GSFBDRA: RMAN VALIDATE HANG WAITING FOR ‘ADR FILE LOCK’ Closed as could not reproduce

Currently we have the following workaround for the issue

RMAN does not write findings to ADR if we set this event.

Setting below event disables updates to the online dictionary .

On every instance of RAC database we need to set event then only it will work :

To solve this problem, Krb tracing needs to enabled on all nodes.

alter system set event=’logon trace name krb_options level 20′ scope=spfile; <==== To set it.
alter system set event=’logon trace name krb_options off’ scope=spfile; <==== To set it off

OR you can set it in RMAN Backup run block as follows.

run
{
sql “alter system set events ”logon trace name krb_options level 20””;
}

Do you want to learn more details About Oracle RMAN, then read the following articles.

RMAN Tutorial | Backup, Restore and Recovery Tutorials For Beginner Oracle DBA