RAID Drive totals not jiving between Array Utility and Disk Management
Posted on 2006-11-30
I have a 2003 server with 5 36.4 gb drives. 3 are currently a logical drive in the array and 2 are unused space in the array. I am looking to add the two drives to the array but before I commit them I have been looking at different numbers and cannot reconcile what I see.
My understanding of RAID 5 - you need a minimum of 3 drives, all drives need to be of equal size, the fault tolerance uses space equaling 1 drive size over the course of the total drives. So if I had 3 drives then 2 would equal available space 1 would be used by RAID Fault Tolerance. If I had 5 drives then 4 would equal available space and 1 would be used by RAID Fault Tolerance, etc...
Looking in Disk Management I show:
Disk 0 - Basic - 101.74 GB Online
C Drive (C:) 67.82 GB NTFS / Healthy (System)
33.92 GB Unallocated
Equaling 101.74 gb
Looking in the HP Array Configuration Utility I show:
1 array controller
1 Parallel scsi array
Under Physical View I show qty 5 of 36.4 gb parallel scsi drives
Equaling 182 gb
Under Logical View I show:
Logical Drive 1 (104183 MB RAID 5)
Unused Space 43410 MB
Equaling 147,593 gb
Logical View Total: 147,593 mb
Physical View Total: 182 gb
Disk Management Total: 101.74 gb
Why is my usable space so much smaller than I expect?
Can anyone explain this for me?