Users Guide

• 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.
RAID 1 characteristics:
• Groups n + n disks as one virtual disk with the capacity of n disks. The controllers currently supported by Storage Management allow
the selection of two disks when creating a RAID 1. Because these disks are mirrored, the total storage capacity is equal to one disk.
• Data is replicated on both the disks.
• When a disk fails, the virtual disk still works. The data is read from the mirror of the failed disk.
• Better read performance, but slightly slower write performance.
• Redundancy for protection of data.
• RAID 1 is more expensive in terms of disk space since twice the number of disks are used than required to store the data without
redundancy.
RAID level 5 -striping with distributed parity
RAID 5 provides data redundancy by using data striping in combination with parity information. Rather than dedicating a physical disk to
parity, the parity information is striped across all physical disks in the disk group.
Understanding RAID concepts
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