dragon-wings
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Joined: Fri Apr 06, 2001 4:55 am

What Is A Raid Controller?

Wed Sep 06, 2006 4:51 am

A few days ago I disconected everything from my computer so I can clean the dust from the inside of the tower. Now when I turn on the computer it says new hardware is detected and to install it. In terms that a computer dummy would understand what is a RAID controller?
Don't give up don't ever give up - Jim Valvano
 
TedTAce
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RE: What Is A Raid Controller?

Wed Sep 06, 2006 5:03 am

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mbmbos
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RE: What Is A Raid Controller?

Wed Sep 06, 2006 5:26 am

Redundant Array of Independent Disks, RAID controllers are used to provide redundancy for mission-critical servers. So, if a hard disk fails, the server keeps running and no data is lost.

Don't know why your home PC would be looking for RAID, unless you purchased a very high-end PC or workstation.
 
RichardPrice
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RE: What Is A Raid Controller?

Wed Sep 06, 2006 5:31 am

A RAID controller is a bit of hardware that can handle writing the same data to multiple disks in a variety of different ways, usually independantly from the OS, and mask from the OS the failure of one of those disks.

RAID stands for Redundant Array of Inexpensive Disks, its a way of maintaining high availability (its available for use most of the time) on a storage solution without having to spend hundreds of thousands on a high availability storage solution OR its a way of increasing the speed of a storage solution without spending the money normally associated, OR its a way of doing both.

RAID works in different ways:

RAID 0 takes two disks and shares the data between them in stripes, making it look as tho the two disks are one big one, and increasing disk access speed at the same time, lose one disk and everything is lost.

RAID 1 takes two disks and mirrors them, everything on disk A also goes on disk B in an identical copy, lose one disk and the other one takes over.

RAID 5 takes multiple disks (usually 5), and uses a mixture of striping and parity to ensure fast access AND the ability to have one disk fail without losing information.

There are a whole host of other RAID levels, doing various interesting things at varying levels.
 
kaddyuk
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RE: What Is A Raid Controller?

Wed Sep 06, 2006 5:42 am

Quoting MBMBOS (Reply 2):
Don't know why your home PC would be looking for RAID, unless you purchased a very high-end PC or workstation.

My hard disks run in RAID 0, because i've two hard disks that are treated as one...
Whoever said "laughter is the best medicine" never had Gonorrhea
 
dragon-wings
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Joined: Fri Apr 06, 2001 4:55 am

RE: What Is A Raid Controller?

Wed Sep 06, 2006 5:47 am

Thanks for the explanations guys.

I do have two hard drives. Don't know if they are treated as one though. (my D drive is used for FS2004 and my C drive is for everything else)

Does anyone know what I should do now about the new hardware being detected?
Don't give up don't ever give up - Jim Valvano
 
TedTAce
Posts: 9098
Joined: Sun Mar 27, 2005 12:31 am

RE: What Is A Raid Controller?

Wed Sep 06, 2006 5:48 am

Quoting MBMBOS (Reply 2):
Don't know why your home PC would be looking for RAID, unless you purchased a very high-end PC or workstation.

Most 'newer' SATA MOBO's have it. Considering most people are still buying PATA, it goes ignored.
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RichardPrice
Posts: 4474
Joined: Sat Apr 23, 2005 5:12 am

RE: What Is A Raid Controller?

Wed Sep 06, 2006 5:54 am

Quoting TedTAce (Reply 6):
Most 'newer' SATA MOBO's have it. Considering most people are still buying PATA, it goes ignored.

Its been a standard feature on all PATA mobos that cost more than a buck fifty for about 4 years.

I dont trust any of these onboard ones tho, they arent worth the silicon they come on. Once the OS is booted, all the hardware functionality is handed over to the drivers and its done by software.

Quoting Dragon-wings (Reply 5):
Does anyone know what I should do now about the new hardware being detected?

Its possible that it was detected earlier, you jsut didnt notice. When you undid everything, you probably changed the order of something when you plugged it all back in again - this will force Windows to redetect everything, prompting for stuff you havent already got drivers installled for.
 
cfalk
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Joined: Mon Dec 04, 2000 6:38 pm

RE: What Is A Raid Controller?

Wed Sep 06, 2006 5:58 am

Quoting RichardPrice (Reply 3):
RAID works in different ways:

RAID 0 takes two disks and shares the data between them in stripes, making it look as tho the two disks are one big one, and increasing disk access speed at the same time, lose one disk and everything is lost.

RAID 1 takes two disks and mirrors them, everything on disk A also goes on disk B in an identical copy, lose one disk and the other one takes over.

RAID 5 takes multiple disks (usually 5), and uses a mixture of striping and parity to ensure fast access AND the ability to have one disk fail without losing information.

Richard has summerized it perfectly.

Many PCs and notebooks sold today (including mine) have a RAID 0 setup. My laptop has 2 60 GB drives coupled into a RAID Array so that it looks and acts like a single 120 GB drive. I suppose they do that because two 60 GB drives would be cheaper than a single 120 GB drive, or maybe they could not get a 12 GB notebook drive at the time.

In normal use, RAID is completely invisible. But there is a downside, which I had the misfortune to run into once. Unlike a normal hard drive, which can be read by a computer's BIOS firmware, a RAID array needs drivers. So if you have a major crash, standard disk-recovery methods won't work. It's a good idea to have a rescue disk set up with the RAID drivers and appropriate utilities in order to access your files in case of disaster.
The only thing you should feel when shooting a terrorist: Recoil.
 
dragon-wings
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Joined: Fri Apr 06, 2001 4:55 am

RE: What Is A Raid Controller?

Wed Sep 06, 2006 5:59 am

Quoting RichardPrice (Reply 7):
When you undid everything, you probably changed the order of something when you plugged it all back in again - this will force Windows to redetect everything, prompting for stuff you havent already got drivers installled for.

I guess that what happened cause when I plugged everything back in I did not do it in the order I un-plugged them. I didn't know that mattered.

So should I just ignore the new hardware detected message?
Don't give up don't ever give up - Jim Valvano

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