A960D+V2
23
4.5 RAID
Function
In a RAID 0 system data are split up in blocks that get
written across all the drives in the array. By using multiple
disks (at least 2) at the same time, this offers superior I/O
performance. This performance can be enhanced further
by using multiple controllers, ideally one controller per
disk.
Features and Benefits
Drives:
Minimum 2, and maximum is up to 6 or 8. Depending on the platform.
Uses:
Intended for non-critical data requiring high data throughput, or any
environment that does not require fault tolerance.
Benefits:
provides increased data throughput, especially for large files. No capacity
loss penalty for parity.
Drawbacks:
Does not deliver any fault tolerance. If any drive in the array fails, all data
is lost.
Fault Tolerance:
No.
Total Capacity:
(Minimal. HDD Capacity) x (Connected HDDs Amount)
Data are stored twice by writing them to both the data
disk (or set of data disks) and a mirror disk (or set of
disks). If a disk fails, the controller uses either the data
drive or the mirror drive for data recovery and continues
operation. You need at least 2 disks for a RAID 1 array.
Features and Benefits
Drives:
Minimum 2, and maximum is 2.
Uses:
RAID 1 is ideal for small databases or any other application that requires fault
tolerance and minimal capacity.
Benefits:
Provides 100% data redundancy. Should one drive fail, the controller
switches to the other drive.
Drawbacks:
Requires 2 drives for the storage space of one drive. Performance is
impaired during drive rebuilds.
Fault Tolerance:
Yes.
RAID 10 combines the advantages (and
disadvantages) of RAID 0 and RAID 1 in one
single system. It provides security by mirroring all
data on a secondary set of disks (disk 3 and 4 in
the drawing below) while using striping across
each set of disks to speed up data transfers.
Features and Benefits
Drives:
Minimum 4, and maximum is 6 or 8, depending on the platform.
Benefits:
Optimizes for both fault tolerance and performance, allowing for automatic
redundancy. May be simultaneously used with other RAID levels in an array, and
allows for spare disks.
Drawbacks:
Requires twice the available disk space for data redundancy, the same
as RAID level 1.
Fault Tolerance:
Yes.
