You have a server named Server1 that runs Windows Server 2012 R2.
You plan to create a storage pool that will contain a new volume.
You need to create a new 600-GB volume by using thin provisioning. The new volume must use the
parity layout.
What is the minimum number of 256-GB disks required for the storage pool?
A.
2
B.
3
C.
4
D.
5
Explanation:
It takes 3 discs (minimum) in order to create a storage pool array with parity. If this array were using
fixed provisioning, this would not be enough given the 256MB capacity (since only 2/3rds of 256 X 3 –
less than 600 – could be used as actual data with the rest being parity bits), but since this array uses
thin provisioning, a 600GB volume could technically be set up on a 20GB disc and it would still show
as 600GB. (So, essentially, the question really becomes how many drives it takes in a storage pool to
create a parity array.)
References:
http://technet.microsoft.com/en-us/library/hh831391.aspx
http://www.ibeast.com/content/tools/RaidCalc/RaidCalc.asp
http://www.raid-calculator.com/default.aspx
https://www.icc-usa.com/raid-calculator
Tested in my lab. Answer is 3 Disks ==> B
I agree with T-BONES. Furthermore, the Explanation given is also correct imho, but the answer is just marked wrong – C instead of B – 4 instead of 3 disks…
Parity – This is a striped set with distributed parity by striping data and parity information across multiple disks, similar to RAID 5. It increases reliability with reduced capacity. This configuration requires at least (!)three(!) disks to protect data from a single disk failure, and cannot be used in a failover cluster.
http://blogs.technet.com/b/yungchou/archive/2012/08/31/windows-server-2012-storage-virtualization-explained.aspx
The answer is B. (!)Thin(!) provisioned means ONLY virtual limits (MAX 64 TB within 2012 R2)
(!)Thick(!) provisioned the answer would be C.
What you tested in your lab?
The question asked, the solution must have:
1. Parity
2. A 600GB volume size
To create a volume with parity (RAID5) you need atleast 3 disks, but you can use only 2 disk equivalent space that is 256X2=512GB and this does not fulfill the requirements.
So, you will 4 disks (you will get 3 disks equivalent space) to reach 600GB.
I am agree with Rez
IMO The answer should be B
Simply put it is because the scenario mentions thin provisioning and the explanation informs us that since this array uses thin provisioning, a 600GB volume could technically be set up on a 20GB disc and it would still show as 600GB. (So, essentially, the question really becomes how many drives it takes in a storage pool to create a parity array.)
The answer is 3 drives minimum to create a storage pool with parity