# What is the purpose of RAID ?



## leachim (Aug 30, 2008)

I have a computer which one or both of the 2 80gb drives has become corrupted - they are connected to a RAID outlet on the MB

Is not the purpose of RAID to clone the other as a backup and how do you recover the good disk if one is bad ??

Mike


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## lazareth1 (Jan 10, 2005)

Well that is way way to do RAID. You are right in the fact that RAID is primarily used to provide redundancy. There is one RAID setup however that do this at all and is RAID 0. This stripes the data accross 2 seperate hard disks to speed up hard disk read/write times. If one fails however, then the whole array as its known cannot be repaired or recovered hence why its trully not RAID or RAID 0. 

The thing is yours could be setup as RAID 1 which is what you have stated. One drive is cloned to the other.

To find out which setup you have, How did the 2 disks appear in my computer? as one disk as 160GB?, 2 disks of 80GB? or just one disk of 80GB?


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## leachim (Aug 30, 2008)

lazareth1 said:


> Well that is way way to do RAID. You are right in the fact that RAID is primarily used to provide redundancy. There is one RAID setup however that do this at all and is RAID 0. This stripes the data accross 2 seperate hard disks to speed up hard disk read/write times. If one fails however, then the whole array as its known cannot be repaired or recovered hence why its trully not RAID or RAID 0.
> 
> The thing is yours could be setup as RAID 1 which is what you have stated. One drive is cloned to the other.
> 
> To find out which setup you have, How did the 2 disks appear in my computer? as one disk as 160GB?, 2 disks of 80GB? or just one disk of 80GB?



I think I have discovered it is a Striped Array, which means that if 1 goes, then so does the other one.

I remember seeing the word Striped on startup

Oh well


Cheers


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## lazareth1 (Jan 10, 2005)

You can double check by going into the RAID BIOS (Not the system BIOS) and checking the array there. If its mirrored (RAID 1) Then you can rebuild the array and save your data. If it's striped then yeah all the data is gone. 

At this point you can recreate the array as RAID 1 (mirrored) or RAID 0 (striped). You might go with RAID 1 this time seeing as what has transpired but you will see a performance hit compared to RAID 0 which is designed to give you better read/write.


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