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Q: What is
the difference between data backup, online backup, image copy
and RAID?
A: Backup refers to the copying of data so that these additional copies may be restored after a data loss event.
Data is considered anything that a user stores such as
documents, pictures, videos, music, address books, email and
databases used by programs like Quicken.
Data loss can be the direct result from failed hardware,
virus, theft, sabotage and natural disaster. The methods of
backing up vary as described below:
Data Backup:
A basic data backup consists of selected files copied to any
number of magnetic media sources such as Tape Drives, External
Hard Drives, NAS Devices, CDRW/DVDRW Drives and Flash Media
products. A data backup can be done by
manually copying files or by the use of a program that
schedules a task automatically.
Online Backup:
A client program is used to schedule a backup to a remote
computer via the internet. This program compresses,
encrypts, and transfers selected files and data to a remote
backup service provider's servers.
Image Copy:
A disk image is a computer file(s) containing the complete contents and structure of
a computer hard drive and can be stored on any number of
magnetic media sources such as Tape Drives, External Hard
Drives, NAS Devices, CDRW/DVDRW Drives and Flash Media
products.
RAID:
Originally stood for "redundant array of inexpensive drives (or
disks)", also known as "redundant array of independent drives (or
disks)" refers to a data storage scheme using multiple hard drives to share or replicate data among the drives.
The most commonly used levels of RAID are RAID1 and
RAID5.
- RAID1 consists of a minimum of 2 disks. The array provides fault tolerance
by the continuous mirroring between both drives. In the
event either drive fails, the other drive can be booted
from normally.
- RAID5 consists of a minimum of 3 disks. In the
event 1 drive fails, the other 2 drives will continue to
operate as normal (but in risk mode). The failed
drive is usually replaced without system shut down and the
task of replacing is usually completely masked by end
users in a server centric scenario.
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