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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:
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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.
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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.
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