Chapter 3. Cluster Software Installation and Configuration
After installing and configuring the cluster hardware, the cluster system software can be installed. The following sections describe installing and initializing of cluster software, checking cluster configuration, configuring syslog event logging, and using the cluadmin utility.
Steps for Installing and Initializing the Cluster Software
Before installing Red Hat Cluster Manager, be sure to install all of the required software, as described in the Section called Kernel Requirements in Chapter 2.
In order to preserve the existing cluster configuration database when running updates to the cluster software, back up the cluster database and stop the cluster software before reinstallation. See the Section called Updating the Cluster Software in Chapter 8 for more information.
To install Red Hat Cluster Manager, invoke the command rpm --install clumanager-x.rpm, where x is the version of Red Hat Cluster Manager currently available. This package is installed by default in Red Hat Enterprise Linux AS so it is typically not necessary to manually install this individual package.
To initialize and start the cluster software, perform the following tasks:
Edit the /etc/sysconfig/rawdevices file on both cluster systems and specify the raw device special files and character devices for the primary and backup quorum partitions. See the Section called Configuring Quorum Partitions in Chapter 2 and the Section called Editing the rawdevices File for more information.
Run the /sbin/cluconfig utility on one cluster system. If updating the cluster software, the utility will inquire before using the the existing cluster database. The utility will remove the cluster database if it is not used.
The utility will prompt for the following cluster-specific information, which will be entered into the member fields in the cluster database. A copy of this is located in the /etc/cluster.conf file:
Raw device special files for the primary and backup quorum partitions, as specified in the /etc/sysconfig/rawdevices file (for example, /dev/raw/raw1 and /dev/raw/raw2)
Cluster system host names that are returned by the hostname command
Number of heartbeat connections (channels), both Ethernet and serial
Device special file for each heartbeat serial line connection (for example, /dev/ttyS1)
IP host name associated with each heartbeat Ethernet interface
IP address for remote cluster monitoring, also referred to as the "cluster alias". Refer to the Section called Configuring the Cluster Alias for further information.
Device special files for the serial ports to which the power switches are connected, if any (for example, /dev/ttyS0), or IP address of a network attached power switch.
Power switch type (for example, RPS10 or None if not using power switches)
The system will prompt whether or not to enable remote monitoring. Refer to the Section called Configuring the Cluster Alias for more information.
See the Section called Example of the cluconfig Utility for an example of running the utility.
After completing the cluster initialization on one cluster system, perform the following tasks on the other cluster system:
Run the /sbin/cluconfig --init=raw_file command, where raw_file specifies the primary quorum partition. The script will use the information specified for the first cluster system as defaults. For example:
cluconfig --init=/dev/raw/raw1
Check the cluster configuration:
Invoke the cludiskutil utility with the -t option on both cluster systems to ensure that the quorum partitions map to the same physical device. See the Section called Testing the Quorum Partitions for more information.
If using power switches, invoke the clustonith command on both cluster systems to test the remote connections to the power switches. See the Section called Testing the Power Switches for more information.
Optionally, configure event logging so that cluster messages are logged to a separate file. See the Section called Configuring syslog Event Logging for information.
Start the cluster by invoking the cluster start command located in the System V init directory on both cluster systems. For example:
service cluster start
After initializing the cluster, proceed to add cluster services. See the Section called Using the cluadmin Utility and the Section called Configuring a Service in Chapter 4 for more information.
Editing the rawdevices File
The /etc/sysconfig/rawdevices file is used to map the raw devices for the quorum partitions each time a cluster system boots. As part of the cluster software installation procedure, edit the rawdevices file on each cluster system and specify the raw character devices and block devices for the primary and backup quorum partitions. This must be done prior to running the cluconfig utility.
If raw devices are employed in a cluster service, the rawdevices file is also used to bind the devices at boot time. Edit the file and specify the raw character devices and block devices that you want to bind each time the system boots. To make the changes to the rawdevices file take effect without requiring a reboot, perform the following command:
service rawdevices restart |
The following is an example rawdevices file that designates two quorum partitions:
# raw device bindings # format: <rawdev> <major> <minor> # <rawdev> <blockdev> # example: /dev/raw/raw1 /dev/sda1 # /dev/raw/raw2 8 5 /dev/raw/raw1 /dev/sdb1 /dev/raw/raw2 /dev/sdb2 |
See the Section called Configuring Quorum Partitions in Chapter 2 for more information about setting up the quorum partitions. See the Section called Creating Raw Devices in Chapter 2 for more information on using the raw command to bind raw character devices to block devices.
 | Note |
|---|---|
The rawdevices configuration must be performed on both cluster members. |
Configuring the Cluster Alias
A cluster alias is a means of binding an IP address to one of the active cluster members. At any point in time this IP address will only be bound by one of the cluster members. This IP address is a useful convenience for system management and monitoring purposes. For example, suppose an administrator wishes to be able to telnet into an active cluster member, but does not care which cluster member. In this case, simply telnet to the cluster alias IP address (or associated name). The principal usage of the cluster alias is to enable the direction of the cluster GUI monitoring interface to connect to an active cluster member. In this manner, if either of the cluster members are not currently active it is still possible to derive cluster status while being abstracted from having to designate a specific cluster member to connect to.
While running cluconfig, you will be prompted as to whether or not you wish to configure a cluster alias. This appears as the following prompt:
Enter IP address for cluster alias [NONE]: 172.16.33.105 |
As shown above, the default value is set to NONE, which means that there is no cluster alias, but the user overrides this default and configures an alias using an IP address of 172.16.33.105. The IP address used for a cluster alias is distinct from the IP addresses associated with the cluster member's hostnames. It is also different from IP addresses associated with cluster services.
Enabling Remote Monitoring
While running cluconfig to specify cluster configuration parameters, the utility will prompt for the following:
Do you wish to enable monitoring, both locally and remotely, via \ the Cluster GUI? yes/no [yes]: |
Answering yes enables the cluster to be locally and remotely monitored by the cluster GUI. This is currently the only security provision controlling cluster monitoring access. The cluster GUI is only capable of performing monitoring requests and cannot make any active configuration changes.
Answering no disables Cluster GUI access completely.
Example of the cluconfig Utility
This section details an example of the cluconfig cluster configuration utility, which prompts you for information about the cluster members, and then enters the information into the cluster database. A copy of this is located in the cluster.conf file. In this example, the information entered in cluconfig prompts applies to the following configuration:
On the storage0 cluster system:
Ethernet heartbeat channels: storage0 Power switch serial port: /dev/ttyC0 Power switch: RPS10 Quorum partitions: /dev/raw/raw1 and /dev/raw/raw2
On the storage1 cluster system:
Ethernet heartbeat channels: storage1 and cstorage1 Serial heartbeat channel: /dev/ttyS1 Power switch serial port: /dev/ttyS0 Power switch: RPS10 Quorum partitions: /dev/raw/raw1 and /dev/raw/raw2
IP address to be used for the cluster alias: 10.0.0.154
/sbin/cluconfig
Red Hat Cluster Manager Configuration Utility (running on storage0)
- Configuration file exists already.
Would you like to use those prior settings as defaults? (yes/no) [yes]: yes
Enter cluster name [Development Cluster]:
Enter IP address for cluster alias [10.0.0.154]: 10.0.0.154
--------------------------------
Information for Cluster Member 0
--------------------------------
Enter name of cluster member [storage0]: storage0
Looking for host storage0 (may take a few seconds)...
Enter number of heartbeat channels (minimum = 1) [1]: 1
Information about Channel 0
Channel type: net or serial [net]:
Enter hostname of the cluster member on heartbeat channel 0 \
[storage0]: storage0
Looking for host storage0 (may take a few seconds)...
Information about Quorum Partitions
Enter Primary Quorum Partition [/dev/raw/raw1]: /dev/raw/raw1
Enter Shadow Quorum Partition [/dev/raw/raw2]: /dev/raw/raw2
Information About the Power Switch That Power Cycles Member 'storage0'
Choose one of the following power switches:
o NONE
o RPS10
o BAYTECH
o APCSERIAL
o APCMASTER
o WTI_NPS
Power switch [RPS10]: RPS10
Enter the serial port connected to the power switch \
[/dev/ttyS0]: /dev/ttyS0
--------------------------------
Information for Cluster Member 1
--------------------------------
Enter name of cluster member [storage1]: storage1
Looking for host storage1 (may take a few seconds)...
Information about Channel 0
Enter hostname of the cluster member on heartbeat channel 0 \
[storage1]: storage1
Looking for host storage1 (may take a few seconds)...
Information about Quorum Partitions
Enter Primary Quorum Partition [/dev/raw/raw1]: /dev/raw/raw1
Enter Shadow Quorum Partition [/dev/raw/raw2]: /dev/raw/raw2
Information About the Power Switch That Power Cycles Member 'storage1'
Choose one of the following power switches:
o NONE
o RPS10
o BAYTECH
o APCSERIAL
o APCMASTER
o WTI_NPS
Power switch [RPS10]: RPS10
Enter the serial port connected to the power switch \
[/dev/ttyS0]: /dev/ttyS0
Cluster name: Development Cluster
Cluster alias IP address: 10.0.0.154
Cluster alias netmask: 255.255.254.0
Serial port connected to the power switch \
[/dev/ttyS0]: /dev/ttyS0
Cluster name: Development Cluster
Cluster alias IP address: 10.0.0.154
Cluster alias netmask: 255.255.254.0
--------------------
Member 0 Information
--------------------
Name: storage0
Primary quorum partition: /dev/raw/raw1
Shadow quorum partition: /dev/raw/raw2
Heartbeat channels: 1
Channel type: net, Name: storage0
Power switch IP address or hostname: storage0
Identifier on power controller for member storage0: storage0
--------------------
Member 1 Information
--------------------
Name: storage1
Primary quorum partition: /dev/raw/raw1
Shadow quorum partition: /dev/raw/raw2
Heartbeat channels: 1
Channel type: net, Name: storage1
Power switch IP address or hostname: storage1
Identifier on power controller for member storage1: storage1
--------------------------
Power Switch 0 Information
--------------------------
Power switch IP address or hostname: storage0
Type: RPS10
Login or port: /dev/ttyS0
Password: 10
--------------------------
Power Switch 1 Information
--------------------------
Power switch IP address or hostname: storage1
Type: RPS10
Login or port: /dev/ttyS0
Password: 10
Save the cluster member information? yes/no [yes]:
Writing to configuration file...done
Configuration information has been saved to /etc/cluster.conf.
----------------------------
Setting up Quorum Partitions
----------------------------
Running cludiskutil -I to initialize the quorum partitions: done
Saving configuration information to quorum partitions: done
Do you wish to enable monitoring, both locally and remotely, via the \
Cluster GUI? yes/no [yes]: yes
----------------------------------------------------------------
Configuration on this member is complete.
To configure the next member, invoke the following command on that system:
# /sbin/cluconfig --init=/dev/raw/raw1
See the manual to complete the cluster installation |