Oracle Cloud Infrastructure Documentation

Perform Prerequisites for Patching

Here's information on the required prerequisites to correctly configure and set up your Oracle Cloud environment to be able to use Observability and Management Patching.

General Prerequisites

The following is a list of general prerequisites required in order to successfully perform patch operations.
Note

Currently only External Databases running on on-premise or Oracle Cloud Infrastructure Virtual Machines on Linux operating system are supported.
  • Install the Management Agent, the Oracle Cloud Infrastructure Management Agent service enables the communication and data collection between Database Management and an External Database.

    For information on how to install Management Agents, see Install Management Agents.

  • Create a DBLM directory under /opt/oracle/dblm for all hosts containing databases to be patched. Set the directory permission as 750, and set the ownership to the Management Agent user and its primary group.

    This directory will contain all the script execution results.

    The patching scripts will be copied into this directory for execution.

  • A new Patch user must be created in all the hosts where the database to be patched is installed.
    Note

    For RAC databases the Patch user must have password-less SSH equivalence. This is required when executing scripts on RAC nodes where the Management Agent is not running. For more information see: About Passwordless SSH Configuration.
  • The Patch user's primary group must be same as Oracle Home owner's primary group.
  • The Patch user must be added to Management Agent user's primary group.
  • The Management Agent user must be added to Oracle Home owner's primary group.
  • The Oracle Home owner must be added to Management Agent user's primary group
  • SUDO must be setup on all the database hosts.
  • Permissions must be added in the SUDOERS file to allow the following user switches
    • Switch the Management Agent user to Patch user
    • Switch the Patch user to Oracle Home/root user
    • Switch the Oracle Home user to a Patch user, and grant the ability to execute limited scripts and commands.

    On hosts where Management Agent is running, the Management Agent user will only switch as the Patch user, and then the Patch user will switch to the Oracle Home/root user for patching.

    The Management Agent is installed on only one of the RAC nodes, all other RAC nodes must have permissions in the SUDOERS file to switch the Patch user to Oracle Home/root user, and Oracle Home user as Patch user.

Required Users, Directories, and Utilities

The following users, directories, and utilities are required to correctly orchestrate the patching process:
User Example
Patch user patchUser
Database Home owner oracle
Database Home owner primary group oinstall
Management Agent user mgmt_agent
Management Agent user primary group mgmt_agent
Directories and Utilities Required Location example
SUDO location /scratch/sudo_setup/bin/sudo
Sudoers file Location /scratch/sudo_setup/etc/sudoers
DBLM directory /opt/oracle/dblm

Patching Prerequisite Tasks to be Completed

Task Command More Information & Examples
Create the DBLM directory across all hosts with correct permissions 
mkdir <DBLM_DIRECTORY> 
chmod 750 <DBLM_DIRECTORY>
chown <MGMT_AGENT_USER>:<MGMT_AGENT_PRIMARY_GROUP><DBLM_DIRECTORY>
 
mkdir $DBLM_DIRECTORY
chmod 750 $DBLM_DIRECTORY
chown
$MGMT_AGENT_USER:$MGMT_AGENT_PRIMARY_GROUP
$DBLM_DIRECTORY
Create the Patch user in all the hosts 
useradd <PATCH_USER>
 Patch user will be used to run the patching scripts as either Oracle Home or root user

For RAC databases, the Patch user must have password-less SSH equivalence across the nodes to run the scripts on RAC nodes where the Management Agent is not running.
Set the Patch user's primary group to be the same as Oracle Home owner's primary group 
/usr/sbin/usermod -g
<DB_HOME_OWNER_PRIMARY_GROUP> <PATCH_USER>
 patchUser details: 
uid=5436(patchUser) 
gid=59968(oinstall)
groups=59968(oinstall)
Add the Patch user to the Management Agent user's primary group 
/usr/sbin/usermod -a <PATCH_USER> -G
<MGMT_AGENT_PRIMARY_GROUP>
 patchUser details: 
uid=5436(patchUser) 
gid=59968(oinstall) 
groups=59968 (oinstall),1486 (mgmt_agent)
Add the Management Agent user must to the Oracle Home owner's primary group 
/usr/sbin/usermod -a <MGMT_AGENT_USER> -G
<DB_HOME_OWNER_PRIMARY_GROUP>
 mgmt_agent details: 
uid=495(mgmt_agent) 
gid=1486 (mgmt_agent) 
groups=1486 (mgmt_agent),8500 (oinstall)
Add the Oracle Home owner to the Management Agent user's primary group 
/usr/sbin/usermod -a <DB_HOME_OWNER> -G
<MGMT_AGENT_PRIMARY_GROUP>
 oracle user details: 
uid=54326(oracle) 
gid=8500(oinstall) 
groups=8500(oinstall), 8502(dba),1486 (mgmt_agent)