Chapter 4. Defining a New Resource Type

This chapter tells you how to define a new resource type:

• Section 4.1

• Section 4.2

• Section 4.3

It also tells you how to test the results in Section 4.4.

To define a new resource type, you must have the following information:

• Name of the resource type. The name can consist of alphanumeric characters and any of the following:

  - (hyphen) 
  _ (underscore) 
  / 
  . 
  : 
  " 
  =
  @
  , 

  The name cannot contain a space, an unprintable character, or any of the following characters:

  *
  ?
  \
  #

• Name of the cluster to which the resource type will apply.

• If the resource type is to be restricted to a specific node, you must know the node name.

• Order of performing the action scripts for resources of this type in relation to resources of other types:

  • Resources are started in the increasing order of this value

  • Resources are stopped in the decreasing order of this value

    Ensure that the number you choose for a new resource type permits the resource types on which it depends to be started before it is started, or stopped after it is stopped, as appropriate.

    Table 4-1 shows the conventions used for order ranges. The values available for customer use are 201-400 and 701-999.

    Table 4-1. Order Ranges

    Range	Reservation
    1-100	SGI-provided basic system resource types, such as MAC_address
    101-200	SGI-provided system plug-ins that can be started before IP_address
    201-400	User-defined resource types that can be started before IP_address
    401-500	SGI-provided basic system resource types, such as IP_address
    501-700	SGI-provided system plug-ins that must be started after IP_address
    701-999	User-defined resource types that must be started after IP_address

    Table 4-2 shows the order numbers of the resource types provided with the release or available as plug-ins from SGI.

    Table 4-2. Resource Type Order Numbers

    Order Number	Resource Type
    10	MAC_address
    20	volume
    30	filesystem
    201	NFS
    401	IP_address
    411	statd
    502	Samba

• Restart mode, which can be one of the following values:

  • 0 = Do not restart on monitoring failures

  • 1 = Restart a fixed number of times

• Number of local restarts (when restart mode is 1).

• Location of the executable script. This is always /usr/lib/failsafe/resource_types/resource_type_tname .

• Monitoring interval, which is the time period (in milliseconds) between successive executions of the monitor action script; this is only valid for the monitor action script.

• Starting time for monitoring. When the resource group is made online in a cluster node, Linux FailSafe will start monitoring the resources after the specified time period (in milliseconds).

• Action scripts to be defined for this resource type. You must specify scripts for start, stop, exclusive, and monitor, although the monitor script may contain only a return-success function if you wish. If you specify 1 for the restart mode, you must specify a restart script.

• Type-specific attributes to be defined for this resource type. The action scripts use this information to start, stop, and monitor a resource of this resource type. For example, NFS requires the following resource keys:

  • export-info which takes a value that defines the export options for the file system. These options are used in the kexportfs command. For example:

    export-info = rw,wsync,anon=root

  • filesystem which takes a value that defines the raw file system. This name is used as input to the mount command. For example:

    filesystem = /dev/xlv/xlv_object