Raid devices by raid type, Virtual raid devices, Planning the raid configuration – HP LeftHand P4000 Virtual SAN Appliance Software User Manual
Page 34: Data protection, Using raid for data redundancy
RAID devices by RAID type
Each RAID type creates different sets of RAID devices.
contains a description
of the variety of RAID devices created by the different RAID types as implemented on various
storage systems.
Table 8 Information in the RAID setup report
Describes this
This 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 P4300
G2, RAID 5 displays a Device Type of RAID 5 and
subdevices as 8.
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 VMware ESX Server 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, 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, RAID 10, 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 or RAID 10 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.
34
Configuring RAID and Managing Disks