The Fastest RAID

[ItsRobert]

I always wondered which RAID would be the fastest one.
RAID 0 or RAID 5 ?
If the two configurations would have same number of drives,capacity, and speed of drives which one would be faster ?

 

[ricno]

RAID 0 would be faster. When writing to RAID5 there is a checksum that has to be calculated and written and when reading there is one less drive that can help delivering your data as it is used for the parity information.

 

[ItsRobert]

RAID 0 would be faster. When writing to RAID5 there is a checksum that has to be calculated and written and when reading there is one less drive that can help delivering your data as it is used for the parity information.

Does the RAID 0 is the fastest RAID ?

 

[ricno]

Does the RAID 0 is the fastest RAID ?

Yes it is, however with no security, so it is a classic trade off between speed and security of your data.

 

[ItsRobert]

Thanks man

 

[ItsRobert]

Best answer selected by ItsRobert.

 

[spinning rust]

so much more to it than that, you need to know how your controller stripes the drives. my array at work stripes 64k across 2 disks. if my N = odd # of disks then the stipes will not align evenly.

so if we are speaking about 5 disks, a 4 + 1 would give me even striping as compaired to a 5 + 0.

does your controller do IO coalescing? if so, then RAID type playes less of a role in write performance as it will bundle smaller IO into a single IO. Also, RAID 5 really sucks at random writes, sequential writes are not so bad.

file system also plays a role. look at NetApp, they get RAID 10 like performance with their WAFFLE filesystem on RAID 6.

 

[ricno]

my array at work stripes 64k across 2 disks. if my N = odd # of disks then the stipes will not align evenly.

so if we are speaking about 5 disks, a 4 + 1 would give me even striping as compaired to a 5 + 0.

I am not really following you here. What is the benefit of the stripes being spread odd or even across the disks?