ASM Oracle permission issue

 

ORA-12547: TNS:lost contact

This error is very generic and below are the symptoms to it. If you find any of these errors in the log it is probably the permission issue on oracle binary on Oracle Home under grid user. 

RMAN Crosschecks error:

RMAN-03002: failure of backup command at 03/24/2025 13:01:37

RMAN-06059: expected archived log not found, loss of archived log compromises recoverability

ORA-19625: error identifying file <datafile>

ORA-17503: ksfdopn:2 Failed to open file <filename>

ORA-12547: TNS:lost contact

ORA-12547: TNS:lost contact

ASM alert log showing error:

*** 2025-03-24T13:28:11.414105-06:00

*** MODULE NAME:(emagent_SQL_osm_instance) 2025-03-24T13:28:11.414215-06:00

*** ACTION NAME:(FileGroup_Usage) 2025-03-24T13:28:11.414234-06:00

ERROR: submiting READ on /dev/rdsk/<diskname> failed due to kgfknm error

crsctl status:

crsctl status res -t

CRS-4535: Cannot communicate with Cluster Ready Services

CRS-4000: Command Status failed, or completed with errors.

Oracle Alert log:

Fatal NI connect error 12547, connecting to:

 <JDBC>

  VERSION INFORMATION:

        TNS for <OS>: Version 19.0.0.0.0 - Production

        Oracle Bequeath NT Protocol Adapter for Solaris: Version 19.0.0.0.0 - Production

  Version 19.25.0.0.0

  Time: 24-MAR-2025 14:46:06

  Tracing not turned on.

  Tns error struct:

    ns main err code: 12547

TNS-12547: TNS:lost contact

    ns secondary err code: 12560

    nt main err code: 517

Solution:

For all these error, below permission change will fix the issue.

login as grid user, and go to GRID_HOME/bin location

chmod 6751 oracle

ls -lrt oracle

-rwsr-s--x   1 grid oinstall 563794648 Mar 26 20:13 oracle

Oracle Bug reference:

But this was is not applicable for our version. 

Bug details: Bug 36461761 - ASM numerous trace files generated with 'error: submiting read on /dev/rdsk/nnn 'failed due to kgfknm error' messages (Doc ID 36461761.8)

Best Wishes!!

TNS and Listener related issues

Oracle TNS issues(tnasnames.ora)

One of the most common error while connecting to Oracle Database is this one. There are plenty of options that needs to be checked and sometime it takes quite a few hours to figure out the exact issue. In my career, I have seen this so many times and each time I have explored new area of this error.

This is mainly due to tns and listener configuration.

There are couple of other error code as well, related to this.

Like : TNS Could not resolve ,ORA-28040: No matching authentication protocol etc..

In this scenario,  we have to look into below possibilities.

•   Need to check $TNS_ADMIN is properly set to folder $ORACLE_HOME/network/admin or $ORACLE_HOME/network/admin/<context_name>
• check tnsnames.ora, listener.ora and sqlnet.ora is configured properly and the content are well formatted
• check lsnrctl status <dbname> is resolving and showing status as active up and running
• check sqlnet.ora file and see the ifile is referring to correct location.
• there are several properties of sqlnet.ora file those needs to be validated.

few example of issue and solution will be added here as well. which will be containing some reference parameters and content of these mentioned files.