Hi there guys,
I had a sales guy tell me:
Capacities based on 30% R10 / 80% R5-9.
obviously you cant have 30/80 so I am assuming him meant 30/70 which seems to the the average
I am having trouble understanding how the usable figure below came about?
1.9TB MRI SSD
24 Disk (23 usable)
93,794 IOPs
32,038GB Usable
My calculations which I assume are incorrect:
23 usable drives would give 43.7TB RAW @30/70 write/read
30/70
RAID 10 and RAID 5-9
43.7 x0.3 = 13.11 TB RAW would be used for writes
13.11/2 = 6.55TB usable RAID 10
43.7-13.11=30.59TB left RAW
30.59x0.89=27.2251 usable at RAID 5-9
6.55+27.2251=33.784TB usable
30/70
RAID 10 and RAID 5-5
43.7 x0.3 = 13.11 TB RAW would be used for writes
13.11/2 = 6.55TB usable RAID 10
43.7-13.11=30.59TB left RAW
30.59x0.8=24.472TB usable RAID 5-5
6.55+24.472=31.022TB usable
What am I missing?
Cheers