2–10 Planning and Design
Hitachi Simple Modular Storage Copy-on-Write SnapShot User’s Guide
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 of 800 GB.
If ShadowImage is used in addition to SnapShot
6. List the total size of SnapShot P-VOLs. Using the example above:
Total SnapShot P-VOL capacity = 150 GB
7. List the total size of ShadowImage S-VOLs. For example:
Total SI S-VOL = 14 TB (14,000 GB)
8. Divide the total S-VOL capacity by 17. For example:
14,000 GB / 17 = 824 GB
9. Subtract the resulting quotient from 32 TB (the maximum capacity
allowed for concurrent copy systems). For example:
32,000 - 824 GB = 31176 GB
10.From this difference, subtract the SnapShot P-VOL capacity. The
difference must be 0 or greater. For example:
31176 GB - 150 GB = 31026 GB
If your system’s maximum capacity exceeds the maximum allowed
capacity, you can do one or more of the following:
• Change the P-VOL size
• Reduce the number of P-VOLs
• Change the data pool size
• Reduce the number of V-VOLs
• Reduce the lifespan of the V-VOL
• Reduce ShadowImage P-VOL/S-VOL sizes
Operating System Considerations
The following sections provide necessary considerations when planning a
SnapShot system.

Identifying P-VOL and V-VOL

The LU number is used to specify the P-VOL and V-VOL in Navigator 2. In
order to understand the mapping of your Windows disk to an LUN, proceed
as follows:
1. Identify the HLUN of your Windows disk.
a. From the Windows Server 2003 Control Panel, select Computer
Management>Disk Administrator.