356 IBM ProtecTIER Implementation and Best Practices Guide
There are other utilities within the ProtecTIER Planner, such as upgrading from a previous
version (with the importation of historical user data), and customizing any disk performance
information based on unique user scenarios when planning performance.
For more information about capacity planning for a TS7650 Appliance environment, see IBM
System Storage TS7600 with ProtecTIER Version 3.1, SG24-7968.
21.5 Many-to-many replication
When planning a many-to-many replication, you must consider potential bidirectional
relationships between up to four hubs in a replication grid. With ProtecTIER V3.2, you must
be aware of the following new enhancements and capabilities:
Up to four hubs that replicate between each other.
Each hub can accept local backups.
Nodes can operate in dedicated windows or concurrently.
The planning process of ProtecTIER systems with replication deployed requires more input
and considerations beyond the individual capacity and performance planning needed for a
system that is only used as a local VTL, FSI-CIFs, or OST. When a multiple-site,
many-to-many topology is deployed, the entire configuration, including all hub environments,
must be evaluated. However, the design process for many-to-many replication contains steps
similar to the steps for planning former one-to-one replication groups.
21.5.1 ProtecTIER Planner tool
The ProtecTIER Planner should be used for capacity and performance planning while
manually adapting it to a many-to-many environment at an early stage before the ProtecTIER
deployment. The parameters to be considered are the same ones used in any
System workload: Both local backup and replication, including incoming and outgoing
Network bandwidth: Available and required between the PT nodes on the grid
Time frames: Backup and replication windows or concurrent operation
21.5.2 Total hub capacity
The physical capacity of each hub accommodates replication from all other hubs, local
backup, and spare capacity. A capacity designer must consider:
The change rate for each hub, and the physical data transferred per day
The retention of both local and replicated data at the hub
Plan for a spare capacity greater than 10%, based on the number of spikes and their
21.5.3 Maximum workloads
The maximum capability for each hub is 24 hours of backup and replication (in + out) at
2200 MBps (in a clustered ProtecTIER environment). This figure represents a total daily
workload of 190 TB (86,400 seconds in a 24 hour period x 2200 = 190 TB).