Hitachi AMS2100 User Manual page 85

P-VOL1: ROUNDUP (100 / 15.75) = 7
7 * 15.75 = 110.25 GB, the managed P-VOL Capacity
P-VOL2: ROUNDUP (50 / 15.75) = 4
4 * 15.75 = 63 GB, the managed P-VOL Capacity
3. List all data pools and their sizes. For example:
Data pool 1 = 100 GB
Data pool 2 = 60 GB
4. Calculate managed data pool capacity, using the formula:
ROUNDUP (data pool capacity / 3.2) * 3.2
For example:
Data pool 1: ROUNDUP (100 / 3.2 = 32)
32 * 3.2 = 102.4 GB, the managed data pool capacity
Data pool 2: ROUNDUP (60 / 3.2 = 19)
19 * 3.2 = 60.8 GB, managed data pool capacity
5. Calculate maximum capacity using the following equation:
(Total P-VOL capacity) / 5 + (Total Data Pool capacity) <
= 800 GB
For example:
Total PVOL size = 173.25 GB
Total data pool size = 163.2 GB
Thus:
173.25 GB / 5 = 34.65 GB
34.65 GB + 163.2 GB = 197.85 GB
In this example, the SnapShot maximum capacity is 197.85 GB,
well below the maximum supported capacity shown in
14.
To calculate capacity when SnapShot and TCE are used
1. Add the total managed capacities for SnapShot P-VOLs and TCE
P-VOLs and S-VOLs. For example:
Total SnapShot P-VOL managed capacity = 173 GB
Total TCE P-VOL, S-VOL managed capacity = 221 GB
173 GB + 221 GB = 394 GB
2. Divide the sum by 5. For example:
394 GB / 5 = 77 GB
3. Add the quotient to total data pool capacity. The following uses
the example data pool capacity from above:
77 GB = 61 = 138 GB
Managed capacity is well below maximum supported capacity.
Planning and design
Hitachi AMS 2000 Family Copy-on-Write SnapShot User Guide
Table 2-
2-33