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Glossary
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Command View EVA Storage System Scripting Utility Reference Guide
uninitialized storage system
A state in which the storage system is not ready for use.
See also initialization.
VDisk (virtual disk)
A collection of blocks created on one or more disks that can be used by a host for information 
storage and retrieval.
The host computer sees the virtual disk as “real,” with the characteristics of an identical physical 
disk.
See also active virtual disk, virtual disk copy, virtual disk family, and virtual disk snapshot.
virtual disk copy 
A clone or exact replica of another virtual disk at a particular point in time. Only an active virtual 
disk can be copied. A copy immediately becomes the active disk of its own virtual disk family.
See also active virtual disk, virtual disk family, and virtual disk snapshot.
virtual disk family 
A virtual disk and its snapshot, if a snapshot exists, constitute a family. The original virtual disk is 
called the active disk. When you first create a virtual disk family, the only member is the active 
disk. 
See also active virtual disk, virtual disk copy, and virtual disk snapshot.
virtual disk snapshot 
See snapshot.
Vraid0
A virtualization technique that provides no data protection. Data host is broken down into chunks 
and distributed on the disks comprising the disk group from which the virtual disk was created. 
Reading and writing to a Vraid0 virtual disk is very fast and makes the fullest use of the available 
storage, but there is no data protection (redundancy) unless there is parity.
Vraid1
A virtualization technique that provides the highest level of data protection. All data blocks are 
mirrored or written twice on separate physical disks. For read requests, the block can be read from 
either disk, which can increase performance. Mirroring takes the most storage space because twice 
the storage capacity must be allocated for a given amount of data.