Data
Protection and Availability
RAID protects your data in the unlikely event of a drive failure. If a disk
drive fails in a properly designed RAID system, network clients are unaware
of the incident and they continue on with their work as if nothing happened.
The RAID system continues to perform read/write operations and if a hot
spare is available it automatically becomes part of the array and data that
was on the failed drive is automatically regenerated onto this new drive
in the array.
Without a RAID system, if a disk drive fails you may suffer the following
economic costs:
* Employee downtime costs
* Emergency service costs
* Data restoration costs
* Data re-entry costs
* Employee downtime during data re-entry cost
* Lost sales costs
* Lost customer costs
* Lost opportunity costs
* Intangible costs due to work day disruption
Think of a RAID system as an insurance policy for your data.
Advantages:
- Improved redundancy. Data can withstand even the complete failure
of one hard disk (or sometimes more) without any data loss and without
requiring any data to be restored from backup.
- Improved read performance With both drives operational, reads can
be evenly split between them, reducing per drive I/O loads
RAID 1 uses mirroring to write data to multiple drives. This means that
when you write a file, the file is actually written to two disks. If one
of the disks fails, you simply replace it and rebuild the mirror.
Mirroring is the automated process of writing data to two drives simultaneously.
Mirroring is used to provide redundancy.
If one drive fails, the redundant drive will continue to store the data
and provide access to it. The failed drive can then be replaced and the
drive set can be re-mirrored.
RAID 1 is also known as a mirrored pair and requires two physical disks.
Each physical disk contains the same exact data. When new data is added,
it is added to both physical disks. The server sees the two physical disks
as one logical disk. If either physical disk fails in the array, the remaining
physical disk will function as the logical disk until the failed disk
is replaced
|
New to hosting?
