Disk Groups; Cross Vraid Replication; Cross Vraid Faq - HP 418800-B21 - StorageWorks Modular Smart Array 70 Storage Enclosure User Manual

• In the process of normalizing or being deleted. See normalization.

Disk groups

Disk group is the term for a named pool of storage on a storage system in which virtual disks can be
created. Seeonline and near-online
IMPORTANT:
Unless noted otherwise, the term
groups that are under the control of a host OS or logical volume manager. Storage system disk groups are
managed through HP StorageWorks interfaces and not by logical volume managers.
See also DR groups

Cross Vraid replication

Cross Vraid replication is a feature that allows the copy of a virtual disk to have a different redundancy
level (Vraid) than the source disk. See virtual disk
Implementation of cross Vraid is controller software dependent. See
controller software features - local replication

Cross Vraid FAQ

Can I use cross Vraid when locally or remotely copying any virtual disk? Generally, yes.
However, the source virtual disk must be on a storage system that supports the feature. See
controller software features - local replication
Why would I use cross Vraid? Typically, to create a copy that is smaller than the source virtual disk.
For example, if you copy a disk whose redundancy level is Vraid 1 or Vraid 5 and use a cross Vraid
assignment of Vraid0, the copy will be smaller. This more efficient use of space can be appropriate when
the copy is retained only for a short time and is not intended to be a high availability resource.
Disk groups
A disk group is a named pool of disk space on a storage array in which individual virtual disks can
be created.
IMPORTANT:
Unless noted otherwise in the help, the term disk group applies to storage array disk groups and not to
host volume disk groups that are under the control of a host OS or logical volume manager.
Online and near-online disk categories
When a disk group is created using HP Command View EVA, it is assigned a disk category of online or
near-online. Whenever a virtual disk is created, it assumes the disk category of its disk group.
• Online disk category. The online disk category provides first tier performance and reliability.
All physical disk drives in this category of disk group are dual ported, high performance fibre
channel drives.
• Near-online disk category. The near-online disk category provides second tier performance and
reliability. All physical disk drives in this category of disk group are lower cost, hybrid fibre
channel disk drives. Hybrid drives are dual ported, FATA (Fibre Attached Technology Adapted)
drives.
Typical uses and recommended category are as follows.
432
Virtual disks
disk group categories.
disk group
applies to storage system disk groups and not to host volume disk
maximum log disk size.
redundancy level.
and controller software features - remote
and controller software features - remote
replication.
replication.