Veritas Storage Foundation 5.1 SP1 for Oracle RAC Administrator"s Guide (5900-1512, April 2011)

classes when they meet specified naming, timing, access rate, and storage
capacity-related conditions.
See also Veritas File System (VxFS)
Failover A failover occurs when a service group faults and is migrated to another system.
GAB (Group Atomic
Broadcast)
A communication mechanism of the VCS engine that manages cluster membership,
monitors heartbeat communication, and distributes information throughout the
cluster.
HA (high availability) The concept of configuring the product to be highly available against system
failure on a clustered network using Veritas Cluster Server (VCS).
HAD (High Availability
Daemon)
The core VCS process that runs on each system. The HAD process maintains and
communicates information about the resources running on the local system and
receives information about resources running on other systems in the cluster.
IP address An identifier for a computer or other device on a TCP/IP network, written as four
eight-bit numbers separated by periods. Messages and other data are routed on
the network according to their destination IP addresses.
See also virtual IP address
Jeopardy A node is in jeopardy when it is missing one of the two required heartbeat
connections. When a node is running with one heartbeat only (in jeopardy), VCS
does not restart the applications on a new node. This action of disabling failover
is a safety mechanism that prevents data corruption.
latency For file systems, this typically refers to the amount of time it takes a given file
system operation to return to the user.
LLT (Low Latency
Transport)
A communication mechanism of the VCS engine that provides kernel-to-kernel
communications and monitors network communications.
logical volume A simple volume that resides on an extended partition on a basic disk and is limited
to the space within the extended partitions. A logical volume can be formatted
and assigned a drive letter, and it can be subdivided into logical drives.
See also LUN
LUN A LUN, or logical unit, can either correspond to a single physical disk, or to a
collection of disks that are exported as a single logical entity, or virtual disk, by
a device driver or by an intelligent disk array’s hardware. VxVM and other software
modules may be capable of automatically discovering the special characteristics
of LUNs, or you can use disk tags to define new storage attributes. Disk tags are
administered by using the vxdisk command or the graphical user interface.
main.cf The file in which the cluster configuration is stored.
Glossary286