Installation guide

50 Chapter 2:Hardware Installation and Operating System Configuration
partition. Data consistency is maintained through checksums and any inconsistencies between the
partitions are automatically corrected.
If a system is unable to write to both quorum partitions at startup time, it will not be allowed to join
the cluster. In addition, if an active cluster system can no longer write to both quorum partitions, the
system will remove itself from the cluster by rebooting (and may be remotely power cycled by the
healthy cluster member).
The following are quorum partition requirements:
• Both quorum partitions must have a minimum size of 10 MB.
• Quorum partitions must be raw devices. They cannot contain file systems.
• Quorum partitions can be used only for cluster state and configuration information.
The following are recommended guidelines for configuring the quorum partitions:
• It is strongly recommended to set up a RAID subsystem for shared storage, and use RAID 1 (mir-
roring) to make the logical unit that contains the quorum partitions highly available. Optionally,
parity RAID can be used for high-availability. Do not use RAID 0 (striping) alone for quorum
partitions.
• Place both quorum partitions on the same RAID set, or on the same disk if RAID is not employed,
because both quorum partitions must be available in order for the cluster to run.
• Do not put the quorum partitions on a disk that contains heavily-accessed service data. If possible,
locate the quorum partitions on disks that contain service data that is rarely accessed.
See Partitioning Disks in Section 2.4.4 and Creating Raw Devices in Section 2.4.4 for more informa-
tion about setting up the quorum partitions.
See Section 3.1.1, Editing the
rawdevices File for information about editing the rawdevices
file to bind the raw character devices to the block devices each time the cluster systems boot.
Partitioning Disks
After shared disk storage hardware has been set up, partition the disks so they can be used in the
cluster. Then, create file systems or raw devices on the partitions. For example, two raw devices must
be created for the quorum partitions using the guidelines described in Configuring Quorum Partitions
in Section 2.4.4.
Invoke the interactive fdisk command to modify a disk partition table and divide the disk into parti-
tions. While in fdisk, use the p command to display the current partition table and the n command
to create new partitions.
The following example shows how to use the fdisk command to partition a disk: