Hitachi G200 - Analyzing Workload, Planning Data Paths; Planning Pairs and Pair Volumes

continues to access the P-VOL or is denied access. See Allowing I/O to the
P-VOL after a split—Fence Level options on page 3-10 for more
information.
Analyzing workload, planning data paths
You optimize copy operations and performance by carefully planning
bandwidth, number of data paths and host interface paths, and number of
ports. This is discussed in:
Check with Hitachi Data Systems customer support for more information.
• Analyze write-workload. Bottlenecks severely impact performance, but
the workload data you collect (MB/s and IOPS) help determine the
following key elements that, when sized properly, form a data path that
operates free of bottlenecks under all workload levels:
¢
Amount of bandwidth.
¢
Number of data paths.
¢
Number of host-interface paths.
¢
Number of ports dedicated for TrueCopy on the primary and
secondary systems.
• If you are setting up TrueCopy for disaster recovery, make sure that
secondary systems are attached to a host server. This enables both the
reporting of sense information and the transfer of host failover
information. If the remote site is unattended by a host, you should attach
the storage systems to a host server at the main site so that the system
administrator can monitor conditions.
Planning 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 on page 3-9
• Allowing I/O to the S-VOL on page 3-10
• Allowing I/O to the P-VOL after a split—Fence Level options on page
3-10
• Differential data on page 3-11
• Maximum number of pairs supported on page 3-12
• 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 on page 3-15
3-8
Planning for TrueCopy
Hitachi TrueCopy® User Guide for Hitachi Virtual Storage Platform Gx00 and Fx00 Models