Sun Cluster 3.1 Data Service for DHCP

Planning the Sun Cluster HA for DHCP Installation and Configuration

This section contains the information you need to plan your Sun Cluster HA for DHCP installation and configuration.

Configuration Restrictions

Caution –

Your data service configuration might not be supported if you do not observe these restrictions.

Consider the restrictions in this section to plan the installation and configuration of Sun Cluster HA for DHCP. This section provides a list of software and hardware configuration restrictions that apply to Sun Cluster HA for DHCP only.

For restrictions that apply to all data services, see the Sun Cluster Release Notes.

The Sun Cluster HA for DHCP data service can only be configured as a failover service – DHCP cannot operate as a scalable service and therefore the Sun Cluster HA for DHCP data service can only be configured to run as a failover service.
DHCP server – DHCP has to operate as a DHCP server and not as a relay host.
DHCP single instance – Only one DHCP resource can be configured within Sun Cluster.
DHCP network table – The DHCP network table can be text or binary files and can be mounted as either a Failover File System (FFS) or a Global File System (GFS).

Note –
It is considered best practice when mounting Global File Systems to mount them with the /global prefix and to mount Failover File Systems with the /local prefix. However, be aware that this is simply viewed as best practice.

Configuration Requirements

Caution –

Your data service configuration might not be supported if you do not adhere to these requirements.

Use the requirements in this section to plan the installation and configuration of Sun Cluster HA for DHCP. These requirements apply to Sun Cluster HA for DHCP only. You must meet these requirements before you proceed with your Sun Cluster HA for DHCP installation and configuration.

DHCP component and its dependencies —The Sun Cluster HA for DHCP data service can be configured to protect a DHCP component. This component and its dependencies are briefly described below.

Table 1–3 DHCP components and their dependencies (via -> symbol)


Componet	Description
DHCP server`(Mandatory)`	-> SUNW.HAStoragePlus resource The SUNW.HAStoragePlus resource manages the DHCP File System Mount points and ensures that DHCP is not started until these are mounted.

The DHCP component has a configuration and registration file under /opt/SUNWscdhc/util. These files allow you to register the DHCP components with Sun Cluster.

Example 1–1 DHCP configuration and registration file for Sun Cluster

# cd /opt/SUNWscdhc
# 
# ls -l util/*
total 6
-rwxr-xr-x   1 root     sys         1094 Dec 20 14:44 dhcp_config
-rwxr-xr-x   1 root     sys          514 Dec 20 14:44 dhcp_register
#
# more util/*
::::::::::::::
util/dhcp_config
::::::::::::::
#
# Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
# Use is subject to license terms.
# 
# This file will be sourced in by dhcp_register and the parameters
# listed below will be used.
#
# These parameters can be customized in (key=value) form
#
#        RS - name of the resource for the application
#        RG - name of the resource group containing RS
#      PORT - name of any port number
#        LH - name of the LogicalHostname SC resource
#   NETWORK - name of the DHCP Network, however comprised of following
#					 <network>@<nafo_or_nodename>@<node number>
#    HAS_RS - name of the DHCP HAStoragePlus SC resource
#
#       The following two examples illustrate sample parameters
#       for DHCP on a 2 node cluster (tequila/sunrise)
#
#       Sun Cluster 3.0 using nafo
#
#       NETWORK=192.168.100.0@nafo0@1/192.168.100.0@nafo0@2
#
#       Sun Cluster 3.1 using ipmp
#
#       NETWORK=192.168.100.0@tequila@1/192.168.100.0@sunrise@2
#

RS=
RG=
PORT=
LH=
NETWORK=
HAS_RS=
::::::::::::::
util/dhcp_register
::::::::::::::
#
# Copyright 2003 Sun Microsystems, Inc.  All rights reserved.
# Use is subject to license terms.
#

. `dirname $0`/dhcp_config

scrgadm -a -j $RS -g $RG -t SUNW.gds \
-x Start_command="/opt/SUNWscdhc/bin/start_dhcp \
-R $RS -G $RG -N $NETWORK " \
-x Stop_command="/opt/SUNWscdhc/bin/stop_dhcp \
-R $RS -G $RG -N $NETWORK " \
-x Probe_command="/opt/SUNWscdhc/bin/probe_dhcp \
-R $RS -G $RG -N $NETWORK " \
-y Port_list=$PORT/tcp -y Network_resources_used=$LH \
-x Stop_signal=9 \
-y Resource_dependencies=$HAS_RS
#

Sun Cluster HA for DHCP data service – requires Solaris 8 7/01 (or later) with patches 109077-07 (or later) and 111302-01 (or later) or Solaris 9.
/etc/inet/dhcpsvc.conf parameters – The following /etc/inet/dhcpsvc.conf parameters have to be set.
- DAEMON_ENABLED should always be true
- PATH should point to the Cluster File System for the DHCP network table
- RUN_MODE should always be SERVER
- RESOURCE is set to either SUNWbinfiles or SUNWfiles
  
  The following parameter in etc/inet/dhcpsvc.conf cannot be set
- INTERFACE

Note –

Ensure that /etc/inet/dhcpsvc.conf is consistent on all nodes within Sun Cluster that will host the DHCP service, or is linked on a directory on a Cluster File System.

Note –

With respect to responses to DHCP requests, SUNWbinfiles should be used for the DHCP network table to achieve the best DHCP performance.