two way mirror , three way mirror in server 2012

two way mirror , three way mirror in server 2012

https://social.technet.microsoft.com/Forums/windowsserver/en-US/2e6955b7-b293-4880-8fb3-8b4ce0e02ec9/mirror-in-storage-pool?forum=winserver8gen

Pool requires a quorum of 50% plus drives to be present to survive.

with 3 way mirror - we have a guarantee of surviving 2 disk failure. 

Maintaining the above requirements and providing the guarantee - mandates us to have minimum 5 disks in pool. As if we loose 2, we still have 3 in the pool (>50%) for pool to maintain it's quorum.

https://technet.microsoft.com/en-us/library/jj822938.aspx#BKMK_Step2

http://www.bleepingcomputer.com/tutorials/how-to-configure-storage-spaces-windows-8/

Simple Storage Space

Simple striping, otherwise known as Raid-0, takes multiple drives and combines them into one virtual drive seen by Windows. This allows you to take different drives of different sizes and combine them into a new drive that uses all of the space on each drive. This allows you to quickly add more storage to a storage space that is running low by adding a new physical drive to the pool. This type of storage space is not recommended for critical or irreplaceable data because if one of these drives fails, you lose all of the data on all of the drives.

Two-way Mirroring Storage Space

Two-way mirroring, or Raid-1, is when you take two drives and they mirror each other. This type of storage space provides hardware protection because if one drive fails the data is still safely stored on the other drive. Please note, that when you use this type of storage space you will only be able to use the space of the smallest drive.

Three-way Mirroring Storage Space

Three-way mirroring is similar to two-way mirroring, but requires 5 drives. This storage process provides hardware protection in the event that two drives fail at the same time.

Parity Storage Space

The parity storage space, or Raid-5, allows you to take 3 or more drives and combine all but the last one into one large virtual drive. The last drive is then used as the parity drive that protects you in the event that one drive fails. If second drive fails before you replace the first failed one, you will lose all of your data.