User's Manual

48 USC and USC - LCE
Select Basic Settings
Select the RAID type for the virtual disk from the RAID Level drop-down menu:
• RAID 0 — Stripes data across the physical disks. RAID 0 does not
maintain redundant data. When a physical disk fails in a RAID 0 virtual
disk, there is no method for rebuilding the data. RAID 0 offers good read
and write performance with 0 data redundancy.
•
RAID 1 — Mirrors or duplicates data from one physical disk to another.
If a physical disk fails, data can be rebuilt using the data from the other
side of the mirror. RAID 1 offers good read performance and average write
performance with good data redundancy.
•
RAID 5 — Stripes data across the physical disks, and uses parity
information to maintain redundant data. If a physical disk fails, the data
can be rebuilt using the parity information. RAID 5 offers good read
performance and slower write performance with good data redundancy.
•
RAID 6 — Stripes data across the physical disks, and uses two sets of
parity information for additional data redundancy. If one or two physical
disks fail, the data can be rebuilt using the parity information. RAID 6
offers better data redundancy and read performance but slower write
performance with very good data redundancy.
•
RAID 10 — Combines mirrored physical disks with data striping. If
a physical disk fails, data can be rebuilt using the mirrored data. RAID 10
offers good read and write performance with good data redundancy.
•
RAID 50 — A dual-level array that uses multiple RAID 5 sets in a single
array. A single physical disk failure can occur in each of the RAID 5
without any loss of data on the entire array. Although the RAID 50 has
increased write performance, when a physical disk fails and reconstruction
takes place, performance decreases, data/program access is slower,
and transfer speeds on the array are affected.
•
RAID 60 — Combines the straight block level striping of RAID 0 with the
distributed double parity of RAID 6. Your system must have at least eight
physical disk to use RAID 60. Because RAID 60 is based on RAID 6,
two physical disk from each of the RAID 6 sets could fail without loss
of data. Failures while a single physical disk is rebuilding in one RAID 6
set do not lead to data loss. RAID 60 has improved fault tolerance
because more than half the number of total physical disk must fail for data
loss to occur.
LC1_2.book Page 48 Wednesday, November 18, 2009 9:42 AM