HP XP Racks - Manual (Page 14)

S-VOL P-VOL
3390-MB •
3390-MC •
3390-M
• 3390-MA
3390-A 3390-A
None supported 3390-V
Related topics
•
“Determining capacity of BC Z pairs in XP7 workflow” (page 14) .
•
“BC Z pair creation” (page 38) .
BC Z licensed capacity and licensed capacity requirements
P-VOLs and S-VOLs must have licensed capacity. The total capacity of pair volumes must be less
than the maximum volume capacity to which you are licensed. Volume capacity is counted only
once, even if you use the volume more than once. You do not need to multiply the capacity by the
number of times you will use it.
After you start performing pair tasks, monitor your capacity requirements to keep volumes’ total
size within your purchased capacity.
You can use BC Z volumes in pairs for 30 days beyond the date it exceeds the licensed capacity.
Beyond that time frame, you can only delete BC Z pairs.
For more information about licensed capacity, see the HP XP7 Remote Web Console User Guide.
Related topics
•
“Sharing volumes with Thin Provisioning Z and Smart Tiers Z” (page 27) .
Determining capacity of BC Z pairs in XP7 workflow
Use the following workflow to determine the maximum number of BC Z pairs that you can create
in your XP7 storage system:
1. Determine the number of differential and pair tables your storage system needs to create BC
Z pairs:
For more information about differential and pair tables, see “Differential and pair tables”
(page 14) .
2. Determine the maximum number of BC Z pairs that you can create on your storage system
(see
“Calculating the maximum number of BC Z pairs” (page 16) ).
Related topics
•
“Tables and installed shared memory” (page 15) .
•
“Calculating the number of tables if you are sharing tables” (page 15) .
•
“Software applications that use tables” (page 15) .
Differential and pair tables
Differential tables and pair tables are required to create BC Z pairs. Differential tables are tables
that manage the differential bitmaps. Pair tables are tables that contain the information needed to
manage BC Z pairs. Create enough tables to handle the BC Z pairs you plan to create.
The XP7 storage system uses a single pair table for up to 36 differential tables.
14 Business Copy Z system requirements and planning