HP StorageWorks XP Remote Web Console Software - Manual (Page 12)

Table 2 How the V-VOL Management Table Is Stored When Data Is Lost From the Shared Memory
Microcode Version Items
60–02–xx or later 60–01–xx
In addition to the SVP HDD, a
dedicated area that is automatically
created in the pool when the pool is
created.
If the area is already created with
microcode version 60-01-xx, there is
no need to create the pool again, etc.,
after upgrading to micro-version
60-02-xx or later.
SVP HDD.
The system option mode 460 of the
SVP must be set to ON. You are not
required to set the system option
because this is a factory setting.
Location where V-VOL
management table
memory is stored in shared
memory
When you switch off the power supply.
When the V-VOL management table is
updated, such as during page
allocation, pool creation, and so on.
It is also stored for any pool created
with microcode version 60-01-xx when
the microcode exchange is replaced.
When you switch off the power supply. When the V-VOL
management table in
shared memory is stored
When you switch on the power supply
after shared memory was volatilized
Restoring the data from the dedicated
area in the pool may take more time
compared to restoring data from the
SVP HDD. Therefore, mode 460 = ON
is recommended. When mode 460 =
ON, the data is stored in both the SVP
HDD and the dedicated area in the
pool.
The time required for restoring the
management table from the dedicated
area in the pool depends on the pool
usage or the V-VOL usage. For
example, when the pool usage or the
V-VOL usage is 100 TB, powering on
takes at least 20 minutes more than
usual, depending on the condition of
the storage system.
When you switch on the power supply
after shared memory was volatilized. When the V-VOL
management table in
shared memory is restored
NOTE: Pools are blocked when an attempt to restore data from both the SVP HDD and the
dedicated area in the pool fails (for example due to a HDD failure). If the pools are blocked, call
HP technical support (see
“Calling HP Technical Support” (page 86) ).
Managing Pool Capacity
One of the key features of XP Thin Provisioning is that you can define V-VOLs that have a greater
capacity than the pool capacity. However, if you run out of free space in the pool, the host cannot
expand the data written to the V-VOLs. It is therefore essential to closely monitor pool capacity, so
that you can increase it as needed.
You can monitor pool capacity directly with the XP Thin Provisioning window (see “XP Thin
Provisioning Window” (page 38) ). You can also use Performance Monitor, RAID Manager, P9000
or XP Command View Advanced Edition software Device Manager, and XP Performance Advisor
Software to monitor used pool capacity. For more information on Performance Monitor, see HP
StorageWorks XP24000/XP20000 Performance Monitor User Guide.
12 About XP Thin Provisioning Operations