Disk Arrays
cancel
Showing results for 
Search instead for 
Did you mean: 

How to estimate the capacity needed of Disk Array for 100TB data ?

MA Qiang
Regular Advisor

How to estimate the capacity needed of Disk Array for 100TB data ?

I should consider RAID5、Hotspare Disk and so on.

How to choice the factor to caculte the capacity needed?

Thanks.
2 REPLIES
Uwe Zessin
Honored Contributor

Re: How to estimate the capacity needed of Disk Array for 100TB data ?

It depends on the storage array how it implements RAID-5. Some arrays like EVA or XP have a fixed overhead - e.g. the EVA always uses 4D+1P, the XP has two different levels (5D+1P and 7D+1P ??). Some other arrays (HSG, MSA) always use the equivalent capacity of one physical disk drive, so the overhead is not fixed.
.
Vincent Fleming
Honored Contributor

Re: How to estimate the capacity needed of Disk Array for 100TB data ?

With XP, you have the choice of 2 different RAID-5's, 3D+1P, and 7D+1P. There is also RAID-6 (6D+2P).

So, for 100TB usable, you would need approxminately 1000 of the 146GB drives. (that's 250 RAID groups - about 750 for data, and 250 for parity) for the 3D+1P, and about 865 drives for 7D+1P. (214 4-drive disk groups [which is 107 7D+1P] - again about 750 drives for data, and 214 for parity).

Note that the drives for XP are always sold in 4-packs.

You will want about 16 spares for 1000 drives.

100TB is a BIG array. An EVA cannot hold that many drives, so if you wish to use EVA, you will need 5 EVA8000's, each with about 215 drives.

Of course, if you use larger drives (such as 300GB drives), you can save some money, but you have to consider performance.

Goo dluck,

Vince

No matter where you go, there you are.