Cross-Cluster Quorum Server Configuration

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Cross Cluster Quorum Server Configurations

1 10/7/2004

Cross Cluster Quorum Server configurations

1. Background

In the Quorum Server A.02.00 Release Notes (and prior versions), it is documented that configuring

the Quorum Server to run in a Serviceguard package is supported, but the following type of

configuration is not supported:

• There are two (or more than two) clusters.

• The Quorum Server runs on each cluster as Serviceguard package.

• Each cluster uses another cluster’s Quorum Server packages.

We call this type of Quorum Server configuration a “Cross Cluster Quorum Server configuration”.

HP will now support these types of configurations however, they do require some initial setup

considerations to work properly. The Serviceguard Extension for Faster Failover product (SGeFF)

requires a Quorum Server, and some customers may want to use SGeFF on two clusters, and may

not want to buy extra cluster hardware or nodes just for running the Quorum Server.

This document will describe the requirements and the steps for how to configure a Cross Cluster

Quorum Server configuration. This configuration is supported for both HP-UX and Linux-based

Serviceguard clusters, including clusters utilizing the SGeFF product. The configuration examples

shown here are for Serviceguard on HP-UX clusters, however can also be used for Serviceguard on

Linux clusters by substituting the appropriate commands and file paths for Serviceguard on Linux.

2. Technical background

The Quorum Server Release Notes state, "you should never configure two clusters that use each

other's Quorum Server packages" and "The cmruncl, cmhaltcl, cmrunnode, and cmhaltnode

commands may fail if some nodes in the cluster cannot communicate with others".

With the current Serviceguard implementation, these commands do not fail when the Quorum Server

is not running or not reachable. When cluster re-formation due to some event occurs, the Quorum

Server must be running and reachable, however, the cluster doesn’t need the Quorum Server when it

is started or halted.

To configure the Quorum Server in this Cross Cluster configuration, the user must perform the

following basic steps:

• Start a single node cluster, cluster 1 that has a Quorum Server package.

• Execute cmapplyconf to configure cluster 2 using the Quorum Server running in cluster 1.

• Configure a Quorum Server package on cluster 2.

Summary of content (8 pages)

PAGE 1
Cross Cluster Quorum Server Configurations Cross Cluster Quorum Server configurations 1. Background In the Quorum Server A.02.00 Release Notes (and prior versions), it is documented that configuring the Quorum Server to run in a Serviceguard package is supported, but the following type of configuration is not supported: • There are two (or more than two) clusters. • The Quorum Server runs on each cluster as Serviceguard package. • Each cluster uses another cluster’s Quorum Server packages.
PAGE 2
Cross Cluster Quorum Server Configurations • Run cluster 2. • Halt cluster 1. • Configure cluster 1 as a two node (or more) cluster. • Configure a Quorum Server package on cluster 1. • Run cluster 1. Please refer to section 4 for the detailed steps for this procedure. 3. Considerations for a Cross Cluster Quorum Server Configuration There are some considerations to use a Cross Cluster Quorum Server configuration.
PAGE 3
Cross Cluster Quorum Server Configurations node A node B QS cluster1 power 1 switch power 2 switch node C node D QS cluster2 Figure 1 To avoid this issue where all nodes fail, every cluster node must be connected to separate power circuits as shown in Figure 2, if each node has only one power input.
PAGE 4
Cross Cluster Quorum Server Configurations 4. Procedure for configuring a Cross Cluster Quorum Server configuration The following is an example procedure (for Serviceguard clusters with SGeFF on HP-UX) for the steps to configure a Cross Cluster Quorum Server configuration. A. Configure a temporary 1-node cluster with a Quorum Server package. [On node B] Create a two node cluster configuration ascii file on node B with cmquerycl command as below: # cd /etc/cmcluster # cmquerycl -C cmclconf.
PAGE 5
Cross Cluster Quorum Server Configurations FAILOVER_POLICY FAILBACK_POLICY NODE_NAME AUTO_RUN LOCAL_LAN_FAILOVER_ALLOWED NODE_FAIL_FAST_ENABLED RUN_SCRIPT RUN_SCRIPT_TIMEOUT HALT_SCRIPT HALT_SCRIPT_TIMEOUT SERVICE_NAME SERVICE_FAIL_FAST_ENABLED SERVICE_HALT_TIMEOUT SUBNET CONFIGURED_NODE MANUAL * YES YES NO /etc/cmcluster/qs-pkg-2/qs-pkg-2.ctl NO_TIMEOUT /etc/cmcluster/qs-pkg-2/qs-pkg-2.ctl NO_TIMEOUT qs NO 10 192.168.4.0 # cmmakepkg -s qs-pkg-2.ctl # vi qs-pkg-2.ctl IP[0]=192.168.4.180 SUBNET[0]=192.
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Cross Cluster Quorum Server Configurations HEARTBEAT_IP NETWORK_INTERFACE HEARTBEAT_IP HEARTBEAT_INTERVAL NODE_TIMEOUT FAILOVER_OPTIMIZATION MAX_CONFIGURED_PACKAGES 192.168.2.21 lan21 192.168.4.21 800000 1600000 TWO_NODE 2 Apply the cluster configuration for cluster2: # cmapplyconf -v -C cmclconf.ascii Add Quorum Server package to cluster2: # echo '+' > /etc/cmcluster/qs_authfile # mkdir /var/adm/qs # mkdir qs-pkg-1; cd qs-pkg-1 # cmmakepkg -p qs-pkg-1.config # vi qs-pkg-1.
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Cross Cluster Quorum Server Configurations On node D, apply the configuration and start cluster2: # cmapplyconf -P /etc/cmcluster/qs-pkg-1/qs-pkg-1.config # cmruncl C. Reconfigure cluster1 as a two node cluster that uses the Quorum Server package on cluster2. [On node B] Halt cluster1: # cmhaltcl –f Edit the cluster ascii file and uncomment the lines for node A to make cluster1 into a two node cluster.
PAGE 8
Cross Cluster Quorum Server Configurations Apply the configuration and start cluster1: # cmapplyconf -v -C /etc/cmcluster/cmclconf.ascii # cmapplyconf -v -P /etc/cmcluster/qs-pkg-2/qs-pkg-2.config # cmruncl The steps above can be adapted for regular Serviceguard clusters (without the SGeFF product) on HP-UX or Linux. There can be more than 2 nodes in the clusters if the SGeFF product is not used.