Adding a new data sharing member

When planning to add a new Db2 data sharing member, you must consider how adding the new member will impact shared resources of the group such as coupling facility (CF) structures, ensure that the new member is installed in an appropriate LPAR with sufficient capacity for the group workloads, and configure it with appropriate settings such as subsystem parameters.

• When adding a new member to a group, you might need to make changes during installation to allow more (XCF groups, or more XCF members per group. Or, you might need to widen the locks in the IRLM lock structure (for example, if the structure was initially allocated with a maximum of seven members, and the eighth member is joining the group). For more information, see Cross-system coupling facility component of z/OS.
• Resize coupling facility (CF) resources, and especially the group buffer pool, appropriately to accommodate the new data sharing member. For more information, see Defining coupling facility structures and Group buffer pool sizes.
• Select an appropriate LPAR for the new Db2 data sharing member, and do not install it in the same central processor complex (CPC) as non-duplexed CF structures used by the group. Otherwise, a single CPC failure can bring down the entire data sharing group. For more information, see Planning for coupling facility availability for data sharing.
• Ensure that the CPC has sufficient CPU, memory, and zIIP capacity to handle the workload of the data sharing group.
• Determine appropriate subsystem parameters values for the new Db2 data sharing member. In many cases, the same settings must be used on every member. For more information, see The scope and uniqueness of Db2 subsystem parameters in data sharing.
• If you are installing the new member the same LPAR as an existing member, use the group name for local attachments. For more information, see Group attachments and subgroup attachments.
• Set up dynamic virtual IP addressing (DVIPAs), make necessary adjustments to DDF location aliases for subsetting. For more information, see Group TCP/IP access.