What is RAID?

[OvRiDe]

OvRiDe, you're all over this. Good job. rep+

Want to explain the difference between hard and soft raid?

Absolutely.. Its pretty basic.

Hardware RAID is controlled by the Drive controller itself, thus the name hard or hardware RAID. Whether its SCSI, IDE, or SATA, there is software embedded in the controller to handle the the functions of the RAID. The nice thing about this is when it gets to the OS, the OS will just see it as it would any other disk. Hardware RAID controllers usually include extra RAM to help increase performance and provide extra stability and reliability.

Software RAID is where Software most likely the OS is controlling the RAIDed drives. This is very handy when you don't have a controller with the embedded Hardware to do RAID. Unfortunately I believe you are pretty much limited to RAID 0 or RAID 1 when dealing with Software RAID configurations.

[Drum Thumper]

I would like to point out that to get full benefits from running in RAID (ie 0,1,3,5), you're going to need Win2k Server or Win2k3 Server editions. The XP Pro and Win2k both only support RAID 0.

Of course, you can bypass that little glitch with 3rd party software.

HTH

[OvRiDe]

I would like to point out that to get full benefits from running in RAID (ie 0,1,3,5), you're going to need Win2k Server or Win2k3 Server editions. The XP Pro and Win2k both only support RAID 0.

Of course, you can bypass that little glitch with 3rd party software.

HTH

This is only the case for Software RAID, when it comes to Hardware RAID the OS is oblivious to the fact that is not a single disk volume. No offense I just wanted to make sure that was clarified and didn't confuse anyone.

I apologize, but it appears that I was inaccurate in my statement that Software RAIDS only support RAID 1 and 0. It does appear that both Linux and Windows (including XP) will do Software RAID 5. Here is an article from THG where they explore RAID 5 in Windows XP. I found the last page with the performance charts quite interesting. It demonstrates the performance difference between Hardware RAID setups and Software RAID. I rarely use software RAID, so I probably should have checked before I spoke.

[DaveW]

Redundant Array of Independent Disks.

Actually, it's Redundant Array of Inexpensive Disks. If you think about it logically, independent disks doesn't even make sense. :p

-Dave

[Airbozo]

Then why do you set up your raid controllers (F6) when XP is installing? That would, to me at least, signify that you can get the full beneift of any RAID config out of more than Server 2k or 2k3..

-J

You are correct Minty! For example, My motherboard at home supports raid on the IDE bus. I have setup my system with a striped raid setup for speed (not that significant if you ask me). The _mother_ board (or more correctly, the IDE controller) handles all functions of the raid subsystem _regardless_ of what OS I am booted into.
\

EDIT: BTW this site has a really good graphical animated explanation of different raid levels and how data is transfered;
http://www.acnc.com/04_00.html

[OvRiDe]

Actually, it's Redundant Array of Inexpensive Disks. If you think about it logically, independent disks doesn't even make sense. :p

-Dave

Actually. both are right. Its one of those places where some use independent and some use inexpensive.

http://searchstorage.techtarget.com/...214332,00.html
http://www.answers.com/topic/raid-technology
http://www.pcmag.com/encyclopedia_te...i=50148,00.asp

The last link seems to sum it up the best..

In the late 1980s, the term stood for "redundant array of inexpensive disks," being compared to large, expensive disks at the time. As hard disks became cheaper, the RAID Advisory Board changed "inexpensive" to "independent."

Then why do you set up your raid controllers (F6) when XP is installing? That would, to me at least, signify that you can get the full beneift of any RAID config out of more than Server 2k or 2k3..

-J

I just want to make sure to point out that when you it asks you to press F6 for RAID controllers, it is so you can load a driver for a hardware raid controller. Drumthumper was referring to software RAID. Again when you load a driver for a Hardware RAID controller, the OS does not know that there is more then one drive attached to the Volume, because all of that is being handled by the hardware. Make sense?

[Drum Thumper]

Actually, it's Redundant Array of Inexpensive Disks. If you think about it logically, independent disks doesn't even make sense. :p

-Dave

I've seen it both ways. In fact, on page 326 of the All-In-One CompTIA A+ certification guide, it's list as both in the same sentence. So it's really just a matter of preference.

The Independent Disk monkier came from the days when disks were pricey. The RAID concept is over 20 years old, and storage prices have plummeted since then, so looking at it that way, Redundant Array of Independent Disks does make sense.

[Drum Thumper]

This is only the case for Software RAID, when it comes to Hardware RAID the OS is oblivious to the fact that is not a single disk volume. No offense I just wanted to make sure that was clarified and didn't confuse anyone.

I apologize, but it appears that I was inaccurate in my statement that Software RAIDS only support RAID 1 and 0. It does appear that both Linux and Windows (including XP) will do Software RAID 5. Here is an article from THG where they explore RAID 5 in Windows XP. I found the last page with the performance charts quite interesting. It demonstrates the performance difference between Hardware RAID setups and Software RAID. I rarely use software RAID, so I probably should have checked before I spoke.

My bad. Shouldn't really be posting @ 3 am when I know I should be in bed. Yes, I was referring to Software RAID. Looks like you pretty well have the class straightened out!

[Redundant]

Actually, it's Redundant Array of Inexpensive Disks. If you think about it logically, independent disks doesn't even make sense. :p

-Dave

It should be changed to Redundant Array of Interconnected Drives. That makes the most sense to me.

[XcOM]

i prefur JBOD!!
My old server used mirrored, i used it for stabilty and backup, mainly coz i transfur LOADS of data, Alot of the time, so i want backups, i've only had to restore the drive twice.