When troubleshooting an Oracle RAC environment, the permissions of the Oracle/Grid binaries are critical. An incorrect permission on the Oracle executable can prevent the database from starting properly.
Recently, I came across a situation where the Oracle binary on a RAC node had incorrect permissions.
The Problem
The Oracle binary was located at:
/u01/app/23.26.0.0/grid/bin/oracle
When checking the file permissions, the following output was observed:
[grid@rac-node1 ~]$ ls -lrt /u01/app/23.26.0.0/grid/bin/oracle
-rwxr-x--x. 1 grid oinstall 533899744 Aug 10 13:42 /u01/app/23.26.0.0/grid/bin/oracle
The file was owned by the correct user and group:
Owner: grid
Group: oinstall
However, the required setuid/setgid permissions were missing.
Correct Permission
The Oracle binary should have the required 6755 permission.
To correct it, run:
chmod 6755 /u01/app/23.26.0.0/grid/bin/oracle
Then verify the permissions:
ls -lrt /u01/app/23.26.0.0/grid/bin/oracle
The output should show the s bits, for example:
-rwsr-sr-x. 1 grid oinstall 533899744 Aug 10 13:42 /u01/app/23.26.0.0/grid/bin/oracle
The important points to verify are:
- The owner is
grid - The group is
oinstall - The Oracle binary has the required setuid/setgid permissions
- The permissions include
6755
Why Is 6755 Important?
The 6755 permission consists of:
6 7 5 5
│ │ │ │
│ │ │ └── Others: read + execute
│ │ └─────── Group: read + execute
│ └──────────── Owner: read + write + execute
└───────────────── Setuid + Setgid
The first digit, 6, enables:
4= setuid2= setgid
Therefore:
6 = setuid + setgid
These special permissions are important for Oracle executables because Oracle processes may need to run with the appropriate effective privileges.
Verify the Ownership
Before attempting to start the database, also make sure the ownership is correct:
ls -l /u01/app/23.26.0.0/grid/bin/oracle
It should show:
grid oinstall
If the ownership is incorrect, it should be corrected according to your Oracle installation standards. For example:
chown grid:oinstall /u01/app/23.26.0.0/grid/bin/oracle
Important: Do not change ownership or permissions blindly on a production Oracle environment. Always compare against the expected permissions for the exact Oracle/Grid version and installation configuration.
Check Both RAC Nodes
This is especially important in an Oracle RAC environment.
Do not correct the permission on only one node.
Check the Oracle binary on both RAC nodes:
Node 1
ls -lrt /u01/app/23.26.0.0/grid/bin/oracle
Node 2
ls -lrt /u01/app/23.26.0.0/grid/bin/oracle
If the permission is incorrect on either node, correct it:
chmod 6755 /u01/app/23.26.0.0/grid/bin/oracle
Then verify again:
ls -lrt /u01/app/23.26.0.0/grid/bin/oracle
Both RAC nodes should have consistent ownership and permissions.
Start the Database
After correcting the permissions, try starting the database again.
For example:
srvctl start database -d <DB_NAME>
Then verify the database status:
srvctl status database -d <DB_NAME>
You can also verify the RAC resources using:
crsctl status resource -t
Quick Troubleshooting Checklist
When an Oracle RAC database does not start after installation, and the Oracle binary is suspected, check the following:
# Check Oracle binary
ls -lrt /u01/app/23.26.0.0/grid/bin/oracle
# Check ownership
stat /u01/app/23.26.0.0/grid/bin/oracle
# Correct permissions if required
chmod 6755 /u01/app/23.26.0.0/grid/bin/oracle
# Verify again
ls -lrt /u01/app/23.26.0.0/grid/bin/oracle
# Check RAC database status
srvctl status database -d <DB_NAME>
# Check cluster resources
crsctl status resource -t
Final Takeaway
If an Oracle RAC installation appears successful but the database fails to start, do not overlook file ownership and permissions.
In this case, the Oracle binary was found with:
-rwxr-x--x. 1 grid oinstall ...
After correcting the permissions:
chmod 6755 /u01/app/23.26.0.0/grid/bin/oracle
and ensuring that the file is owned by:
grid:oinstall
the database can be tested again.
Most importantly, perform the verification on both RAC nodes. Inconsistent permissions between nodes can lead to confusing RAC startup problems and make troubleshooting more difficult.
Note: Always validate the expected Oracle binary permissions against the installation documentation and your environment before making changes, particularly on production systems.
