WD my Cloud PR4100

[nf24eg]

Hello, I try to setup my NAS device WD my cloud pr4100, I have 4 TB Seagate*4 drives
As I know if I use RAID 5 it will use the 3 volumes and #4 will be hot spare, so I will have the capacity of 12TB to use + 4TB as hot spare
BUT in this device it show me that Volume 1(1,2,3,4) are = 12TB, and if I made a check mark to use the spare option the volume changes to be (1,2,3) and the capacity become 8 only ??

its even explained in the manual quarter from each disk = 4tb only

any one can explain to me where I go wrong !!!

 

[rafale77]

I don't think you understand how RAID5 works. Better go research it. The behavior you are describing is perfectly normal and there is no such thing as a hot spare in RAID. They are mutually exclusive and conflicting.

Standard RAID levels - Wikipedia

en.wikipedia.org

Standard RAID levels - Wikipedia

en.wikipedia.org

 

[Callinc]

Hello, I try to setup my NAS device WD my cloud pr4100, I have 4 TB Seagate*4 drives
As I know if I use RAID 5 it will use the 3 volumes and #4 will be hot spare, so I will have the capacity of 12TB to use + 4TB as hot spare
BUT in this device it show me that Volume 1(1,2,3,4) are = 12TB, and if I made a check mark to use the spare option the volume changes to be (1,2,3) and the capacity become 8 only ??

its even explained in the manual quarter from each disk = 4tb only

any one can explain to me where I go wrong !!!

It’s because in raid 5 use need three disks active so they each get a parity. Since you select hot spare it holds one drive “offline” and ready to go if one fails