10 Installing Oracle Management Agent Using Shared Oracle Home

This chapter describes how you can install Oracle Management Agents (Management Agent) with the help of a central, shared Oracle home location of an existing Oracle Management Agent (Management Agent).

Overview
Before You Begin
Prerequisites
Installation Procedure
After You Install

Overview

If you want to install additional Management Agents on hosts that share a mounted drive where a Management Agent is already installed, then the best option is to use the software binaries of the shared Oracle home from that mounted drive and configure the remote hosts to be managed by that Management Agent, thus capitalizing on the network visibility and saving hard disk space on the remote hosts. You can achieve this by using the Shared Agent Deployment Wizard, which is a GUI-rich, interactive wizard built into Enterprise Manager Grid Control.

The Shared Agent Deployment Wizard uses the software binaries from the shared Oracle home, and configures an EMSTATE directory on each of the remote hosts for storing configuration files such as emd.properties, targets.xml, log files, and so on. For more information about the EMSTATE directory, see What Is EMSTATE Directory?.

The Management Agent that shares its software binaries, in this context, is called the Master Agent, and the one that is configured with an EMSTATE directory on the remote host is called the Shared Agents or NFS Agents. Technically, the Shared Agent Deployment Wizard does not install a Management Agent; it only uses the software binaries from the shared Oracle home and configures an EMSTATE directory on each of the remote hosts.

Much like the Agent Deployment Wizard, the Shared Agent Deployment Wizard also can be used for installing multiple Management Agents, as a mass deployment. The only difference here is that the Shared Agent Deployment Wizard does not actually install Management Agents on the destination hosts, but it configures those remote hosts to use the software binaries from the shared, already-installed Management Agent location, and hold only the configuration files. The configuration files can be emd.properties, targets.xml, log files, and so on. The location on a host where the configuration files are placed is called EMSTATE directory.

Before You Begin

Before you begin, keep these points in mind:

You can install only on UNIX-based platforms.
You CANNOT use a shared Oracle home of a Management Agent to install a Management Agent on a cluster. If you want to install a Management Agent on a cluster, follow the instructions outlined in Chapter 9, "Installing Oracle Management Agent on a Cluster Using Agent Deployment Wizard".
You can choose to skip the prerequisite check that is run by the Agent Deployment Wizard. To do so, follow these steps:
1. Navigate to the following location in the Oracle home of the OMS:
  
  <ORACLE_HOME>/sysman/prov/agentpush directory
2. Access the agentpush.properties file.
3. Change the value of oracle.sysman.prov.agentpush.step2 to "false", that is oracle.sysman.prov.agentpush.step2=false.
If you want to view the status of an installation or upgrade session that was previously run, click Agent Installation Status in the Deployments screen. However, do not attempt to view the installation status until the installation is complete. If you do, you will see an error.
For accessing the Enterprise Manager Grid Control console, ensure that you use only certified browsers as mentioned in My Oracle Support note 412431.1.

Prerequisites

Before installing the Management Agent using a shared Oracle home, ensure that you meet the following prerequisites.

If you want, you can print out this section and write 'Yes' or 'No' against each prerequisite. This will help you to track the prerequisites you have met and the prerequisites you have not met.

Table 10-1 Prerequisites for Installing Oracle Management Agent Using Shared Agent Deployment Wizard

Requirement	Description	Yes/No
Hardware Requirements	Ensure that you meet the hard disk space and physical memory requirements as described in Appendix A, "Meeting Hardware Requirements".
Operating System Requirements	Ensure that you install the Management Agent only on certified operating systems as mentioned in My Oracle Support note 412431.1.
User and Operating System Group Requirement	Ensure that the destination host where you want to install the Management Agent has the appropriate users and operating system groups created. For information about creating operating system groups and users, see Appendix C, "Creating Operating System Groups and Users Requirements".
Temporary Directory Space Requirements	Ensure that you allocate 400 MB of space for a temporary directory where the executables can be copied. For example, `/tmp` on UNIX hosts and `c:\Temp` on Microsoft Windows hosts.
Central Inventory Requirements	Ensure that you allocate 100 MB of space for the central inventory directory. Also ensure that the central inventory directory is not on a shared file system. If it is already on a shared file system, then switch over to a non-shared file system by following the instructions outlined in My Oracle Support note 1092645.1.
EMSTATE Directory Requirements	Ensure that the EMSTATE directory you specify is empty and has write permission.	shared, mounted
Existing Management Agent Software Requirements	Ensure that you install a Management Agent (Master Agent) on the shared, mounted location. To install a Management Agent on the shared, mounted location, you can use any of the other Management Agent Deployment methods described in this guide.
Existing Management Agent Status Requirements	Ensure that the existing Management Agent (Master Agent) on the shared, mounted location is shut down always and not used for monitoring any targets. This installation is purely for sharing the software binaries with the Shared Agents.
`oraInst.loc` Location Requirements	If the shared Management Agent is not the first Oracle product installation but its Oracle home is shared, then ensure that you verify the `oraInst.loc` location under the /etc directory. If `oraInst.loc` and `inventory_loc` are located in the your home directory, then ensure that you change this entry point to a non-shared location. The oraInst.loc entry should look like this: `inventory_loc=/<any location other than the home directory>/oraInventory` `inst_group=<group to which the user belongs>`
Software Availability Requirements	Although the installation actually is done using a shared Oracle home of an installed Management Agent that might be running on a different host, the Shared Agent Deployment Wizard uses some scripts and files that are available in the Management Agent software package. Therefore, you are expected to maintain a copy of the Management Agent software for the required platform on the OMS host. By default, the software for Oracle Management Agent 11g Release 1 is available on the host where Oracle Management Service 11g Release 1 is running. Note that this Management Agent software is for the platform on which the OMS is running. Therefore, if you want to install Oracle Management Agent 11g Release 1 on a platform that is the same as the one on which the OMS is running, then you already meet this prerequisite; you do not have to take any action. However, if you want to install Oracle Management Agent 11g Release 1 on a platform that is different from the one on which the OMS is running, then ensure that you download the Management Agent software for that platform. For more information about downloading the Management Agent software, see Procuring Oracle Management Agent Software.
Shared Oracle Home Requirements	Ensure that the shared, mounted location is accessible from all destination hosts where you want to install additional Management Agents.
Path Validation Requirements	Validate the path to all command locations. For more information, see Appendix E, "Validating Command Locations".
Destination Host List Requirements	Ensure that you identify the hosts where you want to install the Management Agent. Otherwise, maintain a host list file that contains a list of hosts as described in What Is a Host List File?.
Destination Host Credentials Requirements	Ensure that the destination hosts have the same operating system credentials and file system structure, including the following: Same User names and Group names Same user identifiers (UID) and group identifiers (GUID)
`/etc/hosts` File Requirements	If the destination host and the host on which OMS is running belong to different network domains, then ensure that you update the `/etc/hosts` file on the destination host to add a line with the IP address of that host, the fully-qualified name of that host, and the short name of the host. For example, if the fully-qualified host name is `mypc.cn.company.com` and the short name is `mypc`, then add the following line in the `/etc/hosts` file: `12.123.123.12 mypc.cn.company.com mypc`
Preinstallation/Postinstallation Scripts Requirements	Ensure that the preinstallation and postinstallation scripts that you want to run along with the installation are available on all the destination hosts.
Installing User Requirements	If the central inventory owner and the user installing the Management Agent are different, then ensure that they are part of the same group. Also ensure that the inventory owner and the group to which the owner belongs have read and write permissions on the inventory directory. For example, if the inventory owner is user1, and user installing the Management Agent is user2, then ensure that user1 and user2 belong to the same group, and they have read and write access to the inventory.
Permission Requirements	Ensure that you have read, write, and execute permissions on `oraInventory` on all remote hosts. If you do not have these permissions on the default inventory (typically at `/etc/oraInst.loc`) on any remote host, then you can specify the path to an alternative inventory location by using the `-i <location>` option in the Additional Parameters section. Ensure that you have write permission on the Installation Base Directory and the temporary directory where the executables will be copied. For example, `/tmp` or `c:\Temp`.
SUDO Privilege Requirement	Ensure that you have SUDO privileges to run `root.sh` and `/bin/sh` (UNIX platforms only). The Agent Deployment Wizard uses SUDO to run the root.sh script. You must specify the invoking user's password here. To verify whether you have SUDO privileges to run these files, access the `/etc/sudoers` file and check whether you have a similar entry as shown below. If you do not see a similar entry, then add one. `<user> <hostname>=PASSWD: /home/em/agent11010/agent11g/root.sh, /bin/sh`
SUDOERS File Configuration Requirements	Ensure that you configure /etc/sudoers file so that while running a command using SUDO, you are always prompted for a password. If /etc/sudoers file is configured in such a way that SUDO never prompts for a password, then a directory with the host password as the title gets created in the invoking users home directory.
Default SSH Port Requirements	Ensure that the SSH daemon is running on the default port (that is, 22) on all the destination hosts. If the port is a non-default port, that is, any port other than 22, then update the SSH_PORT property in the following file present in the OMS Instance Base location: `<INSTANCE_HOME>/sysman/prov/resources/Paths.properties`
PubkeyAuthentication Parameter Requirements	Ensure that the `PubkeyAuthentication` parameter is enabled in the `sshd_config` file. To verify the value of this parameter, run the following command: `grep PubkeyAuthentication <SSH_Install_Location>/sshd_config` For example, grep PubkeyAuthentication /etc/ssh/sshd_config The result of this command must be Yes. If the result is No, then edit the `sshd_config` file, set the PubkeyAuthentication value to Yes, and restart the SSH daemon.

Installation Procedure

To install a new Management Agent using a shared Oracle home of a Management Agent, follow these steps:

In Grid Control, click Deployments.
On the Deployments page, from the Agent Installation section, click Install Agent.
On the following page, select Add Hosts to Shared Agent.
In the Hosts section, do the following:
1. From the Platform list, select the platform (operating system) on which you want to install the Management Agent.
2. For Provide Host List, specify the host names or IP addresses of the hosts on which you want to install the Management Agent.You can use a comma (,) or a white space as a separator when specifying multiple hosts.
  
  Alternatively, if you already have a list maintained in a file, then click Get Host Names From File and select that file.
  
  For information about host list file, see What Is a Host List File?.
In the OS Credentials section, do the following:
1. Specify the appropriate operating system user credentials of the destination hosts. The OS credentials that you specify here must be the same for all the selected hosts
2. Select Run root.sh (on UNIX machines only) if you want the application to run this script.
  
  The root.sh script runs after the configuration assistants are run and before the postinstallation scripts (if any) are run. If you do not select this option here, you must manually run root.sh on each node.
In the Destination section, do the following:
1. For NFS Agent Location, specify the complete path to the shared, mounted, shared directory where the Management Agent software is available. This location must be visible on all remote hosts.
2. For State Directory Location, specify the complete path to an appropriate EMSTATE directory for storing configuration files such as emd.properties, targets.xml, log files, and so on, on each host. Every host that shares the Management Agent has its own EMSTATE directory.
  
  For information about EMSTATE directory, see What Is EMSTATE Directory?.
In the Port section, specify the appropriate port on which the Management Agent will communicate.

Note:
Ensure that the port you specify is not busy, otherwise the prerequisite check fails. If you do not specify a port here, then the Agent Deploy application automatically picks up a free port (3872 or in the range of 1830 - 1849).
In the Additional Parameters section, do not specify any value.
In the Management Server Security section, specify the Management Service Registration Password if you want to secure communications between the Shared Agent and the OMS. This password is mandatory if the Master Agent is secure. Alternatively, the super administrator can approve the addition of new agents to Grid Control after the installation is complete.

Note:
If the OMS is secure in a locked state, then only secure Management Agents can upload data to the OMS.
In the Additional Scripts section, do the following:
1. Specify any preinstallation and/or postinstallation scripts that you want to run. These scripts are optional. If you do not want to customize your installation, leave these fields blank and continue.
2. Select Run as Superuser if you want to run these scripts as root.
Click Continue.

As part of this process, the application performs some prerequisite checks before proceeding with the installation. When all the prerequisite checks are complete, the application displays the results. The results include the name, type, and status for all prerequisite checks designed for the installation.

Besides the successfully run prerequisite checks, the prerequisite checks can return either Warning or Failed status messages. For these status messages, you may choose to ignore and continue with the installation (though this is not recommended).

To fix the failed prerequisites, you can either click Retry. The Fixup screen displays the prerequisites that can be automatically fixed, and those that require manual fixes.

Note:

If the installation fails, then review the log files described in Appendix L, "Installation and Configuration Log Files".

After You Install

After you install the Management Agent, do these:

The targets that were already installed on the host before installing the Management Agent are automatically discovered in Enterprise Manager Grid Control. However, the new targets installed after installing the Management Agent are not automatically discovered. Therefore, if you install any new target, and if you want to discover and monitor it in Enterprise Manager Grid Control, then run the agentca script from the <NFSAGENT_STATEDIRECTORY>/bin directory:

<NFSAGENT_STATEDIRECTORY>/bin/agentca