Users Guide

from these volumes for creation of new virtual disks or Online Capacity Expansion (OCE) of existing virtual disks, provided free
space is available.
Choosing RAID levels
You can use RAID to control data storage on multiple disks. Each RAID level or concatenation has different performance and data
protection characteristics.
NOTE: The H3xx PERC controllers do not support RAID levels 6 and 60.
The following topics provide specific information on how each RAID level store data as well as their performance and protection
characteristics:
• Raid level 0 (striping)
• Raid level 1 (mirroring)
• Raid level 5 (striping with distributed parity)
• Raid level 6 (striping with additional distributed parity)
• Raid level 50 (striping over raid 5 sets)
• Raid level 60 (striping over raid 6 sets)
• Raid level 10 (striping over mirror sets)
RAID level 0 (striping)
RAID 0 uses data striping, which is writing data in equal-sized segments across the physical disks. RAID 0 does not provide data
redundancy.
RAID 0 characteristics:
• Groups n disks as one large virtual disk with a capacity of (smallest disk size) *n disks.
• Data is stored to the disks alternately.
• No redundant data is stored. When a disk fails, the large virtual disk fails with no means of rebuilding the data.
• Better read and write performance.
RAID level 1 (mirroring)
RAID 1 is the simplest form of maintaining redundant data. In RAID 1, data is mirrored or duplicated on one or more physical disks. If a
physical disk fails, data can be rebuilt using the data from the other side of the mirror.
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