XCF maintains an entry in the note pad structure for each note in a note pad. The size of the note pad structure is proportional to the number of notes that can exist in the structure at any given time. The following table shows sample structure sizes for different note counts, assuming that the coupling facility is at CFLEVEL 18:

The CF Structure Sizer (CFSizer) can also be used to simplify the task of calculating the sizes of the note pad structures.

The IBM® CF Structure Sizer (CFSizer) can be accessed at www.ibm.com/systems/support/z/cfsizer/. To size a note pad structure, click on the OEM link and input the structure attributes.

When determining the size of a note pad structure, consider the following required structure attributes:

• A list structure type that has 1040 list headers and uses both entry and adjunct data
• A lock table entry count of 0
• Can be altered
• The maximum number of list entries depends on the maximum number of notes that can exist in the structure at any given time. Use the following formula to calculate the number of maximum list entries:

  #max_list_entries = 5736 + #total_notes 

  where #total_notes is the sum of all notes from all note pads that this structure is expected to host.
• A maximum number of data elements that is the same as the maximum number of list entries
• A maximum of 64 data elements per entry
• A list entry can be located by a key value
• An element increment number of 4 (the size of each element is 1024 bytes)
• Both entry keys and secondary keys might be used when processing list entries
• An event monitoring controls (EMC) count of 0
• Resides in a coupling facility of CFLEVEL 9 or higher

After generating the estimated structure sizes from the CFSizer, if you need to change the coupling facility structure size later, there are two ways you can do that:

• Dynamically alter the coupling facility structure size by entering the SETXCF START,ALTER command or issuing the IXLALTER service. However, the actual structure size cannot exceed the maximum structure size value or fall below the minimum structure size value.
• Update the CFRM policy with the new coupling facility size, activate the policy, and then have the operator initiate a rebuild of the structure.