Specifications

Sample Configuration Map for LifeKeeper Pair
locked resources at any given time. LifeKeeper device locking is done at the Logical Unit
(LUN) level. For active/active configurations, each hierarchy must access its own unique
LUN. All hierarchies accessing a common LUN must be active (in-service) on the same
server.
4. Determine your shared memory requirements. Remember to take into account the shared
memory requirements of third-party applications as well as those of LifeKeeper when
configuring shared memory and semaphore parameters. See Tuning in Technical Notes for
LifeKeeper’s shared memory requirements.
Sample Configuration Map for LifeKeeper Pair
This sample configuration map depicts a pair of LifeKeeper servers sharing a disk array subsystem
where, normally, Server 1 runs the application(s) and Server 2 is the backup or secondary server. In
this case, there is no contention for disk resources because one server at a time reserves the entire
disk storage space of the disk array. The disk array controller is labeled “DAC,” and the SCSI host
adapters (parallel SCSI, Fibre Channel, etc.) are labeled “SCSI HA.”
A pair of servers is the simplest LifeKeeper configuration. When you plan a cluster consisting of more
than two servers, your map is even more critical to ensure that you have the appropriate connections
between and among servers. For example, in a multi-directional failover configuration, it is possible
to define communications paths within LifeKeeper when the physical connections do not exist. Each
server must have a physical communication path to every other server in the cluster in order to
provide cascading failover capability.
Storage and Adapter Requirements
Determine your storage and host adapter requirements using the following guidelines:
Storage Devices - Based on your application’s data storage requirements, you will need to determine
the type and number of data storage devices required by your configuration. Your shared files should
8Planning Your LifeKeeper Environment