Specifications

Non-Shared Storage

If planning to use LifeKeeper in a non-shared storage environment, the risk of data corruption that

exists with shared storage is not an issue; therefore, reservations are not necessary. However,

partial or full resyncs and merging of data may be required. To optimize reliability and availability, the

above options should be considered with non-shared storage as well.

Note: For further information comparing the reliability and availability of the different options, see the

I/O Fencing Comparison Chart.

It is important to note that no option will provide complete data protection, but the following

combination will provide almost the same level of protection as reservations.

Configuring I/O Fencing Without Reservations

To configure a cluster to support node fencing, complete the following steps:

1. Stop LifeKeeper.

2. Disable the use of SCSI reservations within LifeKeeper. This is accomplished by editing the

LifeKeeper defaults file, /etc/default/LifeKeeper, on all nodes in the cluster. Add or modify the

Reservations variable to be “none”, e.g. RESERVATIONS=”none”. (Note that this option

should only be used when reservations are not available.)

3. Obtain and configure a STONITH device or devices to provide I/O fencing. Note that for this

configuration, STONITH devices should be configured to do a system “poweroff” command

rather than a “reboot”. Take care to avoid bringing a device hierarchy in service on both nodes

simultaneously via a manual operation when LifeKeeper communications have been disrupted

for some reason.

4. If desired, obtain and configure a quorum/witness server(s). For complete instructions and

information on configuring and using a witness server, see Quorum/Witness Server Support

Packagetopic.

Note: The quorum/witness server should reside at a site apart from the other servers in the

cluster to provide the greatest degree of protection in the event of a site failure.

5. If desired, configure watchdog. For more information, see theWatchdogtopic.

I/O Fencing Chart

Split-Brain Hung Server

Reservations On

Alone

104Configuration