HP StorageWorks XP Remote Web Console Software - Manual (Page 6)

1 About Version 1 Operations
HP StorageWorks XP24000 and XP20000 disk arrays are functionally compatible with Version
1 of the IBM FlashCopy host software function. PPRC TSO commands and/or DFSMSdss commands
may be used to perform Version 1 operations on the storage system. See
“Performing Version 1
Operations” (page 24) for further information on using PPRC TSO commands and DFSMSdss
commands.
This chapter provides an overview of Version 1 operations.
•
“How Version 1 Works” (page 6)
•
“Establishing a Version 1 Relationship” (page 6)
•
“Releasing a Version 1 Relationship” (page 7)
•
“Status of a Relationship” (page 7)
•
“Interoperability with Other Products and Functions” (page 8)
Unless otherwise specified, the term storage system in this guide refers to the following disk arrays:
•
HP StorageWorks XP24000 Disk Array
•
HP StorageWorks XP20000 Disk Array
The GUI illustrations in this guide were created using a Windows computer with the Internet Explorer
browser. Actual windows may differ depending on the operating system and browser used. GUI
contents also vary with licensed program products, storage system models, and firmware versions.
How Version 1 Works
Version 1 provides a fast data replication capability. Version 1 allows you to create a copy of an
S-VOL on a T-VOL virtually or physically. A volume pair created by Version 1 is called a relationship.
Once this relationship is established, the T-VOL (the virtual or physical copy of the S-VOL) is available
for both read and write operations.
When you establish a Version 1 relationship, you can specify a range of data to be copied, which
is called an extent. Version 1 allows you to specify one copy target extent per copy source extent.
Establishing a Version 1 Relationship
Specify Hitachi ShadowImage™ for Mainframe volumes for the copy source or copy target of a
Version 1 relationship. However, you cannot establish a Version 1 relationship if the desired S-VOL
has already three T-VOLs.
There are two types of copying processes for Version 1:
•
Background copying process
The background copying is the process used to copy all the data within a copy range that is
specified when you establish the relationship.
•
On-demand copying process
The on-demand copying is the process used to copy data when a read or write request occurs
to an area that is not yet copied. In this case, the area that requested a read or write access
will be copied before the request is actually executed.
If you do not specify any additional parameter, when the background copy of the extent data is
completed, the relationship ends automatically. If you do not want to release the relationship after
the copy operation completes, you need to establish the relationship in NOCOPY mode. For details,
see
“Establishing a Version 1 Relationship” (page 24) .
6 About Version 1 Operations