HP XP Business Copy Software - Manual (Page 80)

80 Maximum pair calculations
Calculating the number of pairs you can create
If LUSE is not used
The maximum number of pairs that can be created is the largest number that meets the equation ,
where:
• Σ (α) is the total number of differential tables (α) required for creating a copy pair.
• β is the number of available differential tables (13,652 with no additional shared memory, 30,718
with additional shared memory).
For example, if you want to create 20 pairs of OPEN-V volumes, each with 60 GB (62,914,560 KB) of
capacity, 5 differential tables are required for each volume ( ,
which becomes 5 when rounded up to the nearest whole number). The total number of pairs is:
.
Since , you can create 20 pairs without installing additional shared memory.
If LUSE is used
The maximum number of pairs that can be created is the largest number that meets the equation
, where:
• Σ (α) is the total number of differential tables (α) required for creating a copy pair.
• β is the number of available differential tables (13,652 with no additional shared memory, 30,718
with additional shared memory.
For example, if you want to create 20 pairs of LUSE volumes, each consisting of five OPEN-V volumes with
60 GB (62,914,560 KB) of capacity, five differential tables are required for each OPEN-V volume
( , which becomes five when rounded up to the nearest whole
number). The total number of pairs is .
Since , you can create 20 pairs without installing additional shared memory.
Calculating the number of Auto LUN XP concurrent migration plans
When a migration plan is created, differential tables are used. Differential tables are disk array resources
that are shared by Flex Copy XP, Business Copy XP, ShadowImage for z/OS ® , Hitachi FlashCopy
Mirroring, Hitachi FlashCopy Mirroring Version2, Snapshot XP, and Auto LUN XP. The maximum number of
differential tables that Auto LUN XP can use is the number of total differential tables in the disk array minus
the number used by other applications.
When using Auto LUN XP for manual volume migration, the number of migration plans that can be
executed concurrently depends on the following:
• How much shared memory is available for differential tables. The number of differential tables
available in one disk array is determined by whether additional shared memory for differential tables is
installed.
• You can use 13,652 differential tables if no additional shared memory for differential tables is
installed.
• You can use 30,718 differential tables if additional shared memory for differential tables is
installed.
NOTE: Contact your HP account support representative for more information about adding additional
shared memory.
• The emulation type and capacity of each volume to be migrated:
The number of differential tables needed to migrate one volume differs depending on the emulation
type and size of the volume. For the number of differential tables needed for migrating a mainframe
volume, see page 81. For the number of differential tables needed for migrating an open-system
volume, see page 83.
Σ α ( ) β ≤
62,914,560 256 61,312 ч ч 4.0084 =
Σ α ( ) 5 20 × 100 = =
100 13,652 ≤
Σ α ( ) number of volumes that configure a LUSE volume ( ) × [ ] β ≤
62,914,560 256 ч 61,312 ч 4.0084 =
Σ α ( ) 5 Ч 5 20 Ч 5 Ч 500 = =
500 13,652 ≤