782 Implementing the IBM Storwize V7000 with IBM Spectrum Virtualize V8.2.1
Point-in-time copy
A point-in-time copy is an instantaneous copy that the FlashCopy service makes of the source 
volume. See also “FlashCopy service” on page 777.
Preparing phase
Before you start the FlashCopy process, you must prepare a FlashCopy mapping. The 
preparing phase flushes a volume’s data from cache in preparation for the FlashCopy 
operation.
Primary volume
In a stand-alone Metro Mirror or Global Mirror relationship, the target of write operations that 
are issued by the host application.
Private fabric
Configure one SAN per fabric so that it is dedicated for node-to-node communication. This 
SAN is referred to as a private SAN.
Provisioned capacity
See “Capacity” on page 771.
Public fabric
Configure one SAN per fabric so that it is dedicated for host attachment, storage system 
attachment, and remote copy operations. This SAN is referred to as a public SAN. You can 
configure the public SAN to allow Storwize V7000 node-to-node communication also. You can 
optionally use the -localportfcmask parameter of the chsystem command to constrain the 
node-to-node communication to use only the private SAN.
Quorum disk
A disk that contains a reserved area that is used exclusively for system management. The 
quorum disk is accessed when it is necessary to determine which half of the clustered system 
continues to read and write data. Quorum disks can either be MDisks or drives.
Quorum index
The quorum index is the pointer that indicates the order that is used to resolve a tie. Nodes 
attempt to lock the first quorum disk (index 0), followed by the next disk (index 1), and then, 
the last disk (index 2). The tie is broken by the node that locks them first.
RACE engine
The RACE engine compresses data on volumes in real time with minimal effect on 
performance. See “Compression” on page 773 or “Real-time Compression” on page 783. 
Raw capacity
See “Capacity” on page 771.
Real capacity
Real capacity is the amount of storage that is allocated to a volume copy from a storage pool. 
See also “Capacity” on page 771.