10.5 HP StoreVirtual Storage User Guide (AX696-96269, March 2013)

Table 7 Information in the RAID setup report
Describes thisThis item
The disk sets used in RAID. The number and names of
devices varies by storage system and RAID level.
Device Name
The RAID level of the device. For example, in a HP P4300
G2, RAID 5 displays a Device Type of RAID 5 and
subdevices as 8.
NOTE: On the 4730 and the 4630 with 25 drives, since
the global hot spare is configured, each logical drive will
show 13 subdevices (12 data drives plus 1 spare).
Device Type
The RAID status of the device.
Status is one of the following:
Device Status
• Normal—green
• Degraded—yellow
• Off—red
• Rebuilding—blue
The number of disks included in the device.Subdevices
Virtual RAID devices
If you are using the VSA, the only RAID available is virtual RAID. After installing the VSA, virtual
RAID is configured automatically if you first configured the data disk in the VI Client.
HP recommends installing VSA for vSphere on top of a server with a RAID 5 or RAID 6 configuration.
Planning the RAID configuration
Plan the RAID configuration for storage systems based on a balance between data high availability
or fault tolerance, I/O performance, and usable capacity.
CAUTION: Plan your RAID configuration carefully. After you have configured RAID and created
a management group, you cannot change the RAID configuration without deleting all data on the
storage system.
Data protection
Keeping multiple copies of your data ensures that data is safe and remains available in the case
of disk failure. HP recommends using both disk RAID and Network RAID to insure high availability:
• Configure RAID 1+0, RAID 5, or RAID 6 within each storage system to ensure data redundancy.
• Always use Network RAID to mirror data volumes across storage systems in a cluster, regardless
of RAID level, for added data protection and high availability.
Using RAID for data redundancy
Within each storage system, RAID 1+0 ensures that two copies of all data exist. If one of the disks
in a RAID pair goes down, data reads and writes continue on the other disk. Similarly, RAID 5 or
RAID 6 provides redundancy by spreading parity evenly across the disks in the set.
If one disk in a RAID 5 set, or two disks in a RAID 6 set goes down, data reads and writes continue
on the remaining disks in the set.
RAID protects against failure of disks within a storage system, but not against failure of an entire
storage system. For example, if network connectivity to the storage system is lost, then data reads
and writes to the storage system cannot continue.
30 Configuring RAID and Managing Disks