HP XP7 Storage - Manual (Page 18)

Required shared memory capacity Total capacity of all pools
24 GB If the total capacity satisfies both of following:
• More than 3.1 PB
•
7.1 PB or less
40 GB If the total capacity satisfies both of following:
•
More than 7.1 PB
•
11.1 PB or less
TIP: The V-VOL management area is automatically created when shared memory is added. This
area is used to store information for associating pool-VOLs and THP V-VOLs.
If Smart Tiers Z is used to correspond with Thin Provisioning Z, Smart Tiers Z and Fast Snap pools,
additional shared memory must be installed. When using Smart Tiers Z, the following table shows
the required shared memory capacity and the additional shared memory to be installed.
Required shared memory capacity Total capacity of all pools
8 GB 1.0 PB or less
16 GB If the total capacity satisfies both of following:
• More than 1.0 PB
•
3.1 PB or less
32 GB If the total capacity satisfies both of following:
• More than 3.1 PB
•
7.1 PB or less
48 GB If the total capacity satisfies both of following:
• More than 7.1 PB
•
11.1 PB or less
About cache management devices
Cache management devices are associated with volumes (LDEVs) and used to manage caches.
One volume (LDEV) requires at least one cache management device. An entire system can manage
up to 65,280 cache management devices. A THP V-VOL may require more than one cache
management device. This topic describes how to calculate the number of cache management
devices.
Calculating the number of cache management devices required by a THP V-VOL
The number of cache management devices that a THP V-VOL requires depends on the capacity of
the V-VOL (capacity of the user area) and the maximum capacity of cache management device.
The maximum capacity of cache management device depends on the pool attribute (internal volume
or external volume) associated with V-VOL. The following table explains the relationship between
the pool attribute and the maximum capacity of cache management device.
18 Introduction to provisioning