will represent hard disk mirroring method and characteristics , advantages and
disadvantages , Points of failure .
The term RAID was coined in
1987 by David Patterson, Randy Katz and Garth A. Gibson. In their 1988 technical
Disk mirroring or it’s called “redundant array of independent disks”
(RAID) is a technique used to protect computer systems from
losing data or any potential losses due to disk failures. In this technique, Data
will duplicated by saving data in two or more identical hard drives, All hard
drives are connected on one disk controller card. If one hard drive fails, the
data can be taken from other mirrored hard drives.
below illustrates RAID meaning:
(RAID) is technique found to protect data because any system can be break .
After this calamity data will be available whenever you reach this point .
Also, It increases the data acceleration access.
As written in
the problem definition section there are many solutions to solve this problem such
as “Placing Related Blocks on Cylinders ” to increase access speed
this technique read on the same cylinder in the same time . And there is many
other related techniques …
At the hard disk drive data retrieval
evaluation process, all media obtained goes through an analysis to recognize
the real shape of the drive. Few steps to follow through the hard disk drive
data retrieval, and these comprise the following: 1. The hard disk drive data recovery experts will determine whether the issues are physical,
logical, or both. Issues refer to those that happen in the hardware, while
plausible problems occur on the applications structures.
First ,Needing too much of memory capacity ; Because
all data written twice or more. It have
a complex technology . Furthermore, Replacing and restoring the data from a
large file to smaller one may take long time (one or more day) depending on the
speed of controller .
Frequently RAID server has single
controller. If the server failure will result in all single point of failure.
Also , Loss
of RAID configuration settings or system registry can make a failure .
In the 1988 authors determines six
levels of RAID, 0 through 5. This numbering system content uses of redundant data
across the array. This number classified into
three categories: standard, nested and nonstandard RAID levels.
case a drive fails, Data just have to be copied to the replacement drive.
data transactions are very fast while write data transactions are somewhat
Hoping that my report is beneficial and you well understood RAID characteristics.