Raid Group; Raid Level - Hitachi HUS VM Hardware User's Manual

PDU
power distribution unit
pool
A set of volumes that are reserved for storing Copy-on-Write Snapshot data or Dynamic
Provisioning write data.
R
RAID
redundant array of independent disks. A disk array in which part of the physical storage
space is used to store user data and parity information, and another part is used to
store a duplicate set of user data and parity information. This redundant configuration
prevents data loss in case a disk drive within the RAID configuration fails, and enables
regeneration of user data in the event that one of the array's member disks or the
access path to it fails.

RAID group

A set of RAID disks that have the same capacity and are treated as one group for data
storage and recovery. A RAID group contains both user data and parity information.
This allows user data to be accessed in the event that one or more of the drives within
the RAID group are not available. The RAID level of a RAID group determines the
number of data drives and parity drives and how the data is "striped" across the drives.
For RAID1, user data is duplicated within the RAID group, so there is no parity data for
RAID1 RAID groups.
A RAID group can also be called an array group or a parity group.

RAID level

The type of RAID implementation. The HUS VM system supports RAID levels RAID1,
RAID5 and RAID6.
S
SAS
serial-attached SCSI
SATA
serial Advanced Technology Attachment
service information message (SIM)
SIMs are generated by a storage system when it detects an error or service
requirement. SIMs are reported to hosts and displayed on Storage Navigator.
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Hitachi Unified Storage VM Block Module Hardware User Guide
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