HP XP P9500 Storage - Manual (Page 19)

The following table shows example settings.
Round trip
time
specified
[ms] Number of maximum
initial copy VOLs Initial copy pace Number of data
paths between
MCU/RCU Data path speed
between
MCU/RCU
(MB/ms) Round trip time
between MCU RCU
[ms]
160 64 15 4 0.1 0
220 64 15 4 0.1 30
360 64 15 4 0.1 100
Planning for pairs and pair volumes
This section discusses requirements, options, and settings you need for setting up pairs and pair
volumes. You begin by:
•
Identifying data and volumes at the local site that you want to protect with a backup
•
Setting up volumes at the remote site that will hold copied data.
The following helps ensure that the pairs you create fit your requirements.
•
Pair volume requirements and recommendations (page 19)
•
Preparations for allowing I/O to the S-VOL (page 20)
•
Fence Level options for I/O to the P-VOL after suspension (page 21)
•
Differential data options (page 21)
•
Maximum number of pairs supported (page 22)
•
Options and settings for number of pairs copied, and their priority, during the initial copy
and resync operations. See
Priority for initial copy operations and scheduling order (page 24)
Pair volume requirements and recommendations
The following is provided to help you prepare Continuous Access Synchronous volumes:
•
A volume can be assigned to only one Continuous Access Synchronous pair.
•
Continuous Access Synchronous requires a one-to-one relationship between the P-VOL and
S-VOL. The P-VOL cannot be copied to more than one S-VOL, and an S-VOL cannot have more
than one P-VOL.
•
Logical Unit (LU) Types
Continuous Access Synchronous supports the basic LU types that can be configured on
the XP P9500 (for example, OPEN 3, OPEN E, OPEN 8, OPEN 9, OPEN L, OPEN V). ◦
◦ Pair volumes must consist of LUs of the same type and capacity (for example, OPEN 3
to OPEN 3). The P-VOL and S-VOL LU types display in Remote Web Console.
◦ Multi-platform volumes (for example, 3390 3A/B/C) cannot be assigned to pairs. Contact
your HP account team for the latest information about supported devices for your platform.
•
Continuous Access Synchronous operates on volumes rather than on files; multi-volume files
require special attention. For complete duplication and recovery of a multi-volume file (for
example, a large database file that spans several volumes), make sure that all volumes of the
file are copied to Continuous Access Synchronous S-VOL.
•
Continuous Access Synchronous pair volumes can be shared with non-Continuous Access
Synchronous HP software products. See
Sharing Continuous Access Synchronous volumes
(page 38) for more information.
Planning for pairs and pair volumes 19