Summary

Does not require a separate system.

Disk can be used for other purposes as well.

Legacy method that has been used for many years.

Requires separate disk hardware that must be cabled to all nodes.

Can only be used with clusters up to 4 nodes.

Not available on Linux.

Acquiring the lock follows an arbitration protocol, and this adds to failover time.

Use in extended distance clusters requires dual lock disks, with a slight risk of split brain.

Does not require a separate system.

Disk can be used for other purposes as well.

Similar to HP-UX lock disk.

Requires separate disk hardware that must be cabled to all nodes.

Can only be used with clusters up to 4 nodes.

Acquiring the lock follows an arbitration protocol, and this adds to failover time.

Dual lock LUNs are not supported, including extended clusters.

Can be used with clusters of any size.

Can serve up to 50 clusters/100 nodes.

Can be used HP-UX and Linux clusters at the same time.

Is free on the Distributed Components CD (shipped along with the SG product CD).

Provides faster failover time than cluster lock disk.

Requires a separate system not part of the cluster.

Only one IP address is used for quorum server.

Does not permit multiple physical network pathways unless APA (auto port aggregation) or channel bonding is used. LAN failure will remove the QS from communication with the cluster, though the cluster remains running.

Offers protection for the loss of an entire data center in a metropolitan or extended distance cluster.

Allows arbitration to be done over longer distances than disk locking.

Arbitrator nodes can be used for other non-cluster applications.

Additional Serviceguard licenses required for arbitrator nodes.

Additional hardware must be provided, often in a data center that is on a separate site.

For those with multiple clusters, arbitrator nodes can be very costly.