HPE Storage Users Group

Hi Gurus,

Need to ask on how 3PAR calculate the raw, useable capacity, spare using RAID 5 (3+1).

System F400

4 Cages
each cages has 12 disk
disk type FC
capacity for each disk is 600GB

I need to know how to calculate the useable capacity and spare require.

As in system i can see this

cli% showspace -t r5
---Estimated(MB)---
RawFree UsableFree
25907200 19430400

cli% showsys -space
---------System Capacity (MB)----------
Total Capacity : 27451392
Allocated : 1540096
Volumes : 93184
Base Volumes : 0
User : 0
Copy : 0
Admin : 0
CPGs (TPVVs & CPVVs) : 93184
Copy : 44032
Used : 28672
Unused : 15360
Admin : 49152
Used : 16128
Unused : 33024
Unmapped : 0
System : 1446912
Internal : 303104
Spare : 1143808
Used : 0
Unused : 1143808
Free : 25911296
Initialized : 25911296
Uninitialized : 0
Unavailable : 0
Failed : 0

Help me to understand this...really appreciated.