XRC operates in up to 21 address spaces on a single logical partition (LPAR mode). ANTAS000 is always active and processes XRC commands. You can start from 1 to 20 XRC sessions at a time. Each unique XRC session that is started on a system occupies its own address space. (For example, the first address space is ANTAS001, the second is ANTAS002, and so forth through ANTAS020 ). One of these 20 address spaces is used by the ANTCLnnn address space if XRC clustering is enabled. See Address Spaces for XRC for specific information about XRC session address spaces.
The ANTAS000 address space uses 65 MB of virtual storage, which includes a 20 MB trace data space.
Recommendation: Do not restrict the virtual storage that is used by the ANTASnnn address spaces. However, if you need to limit virtual storage usage, the following provides a guideline as to the amount of virtual storage that is needed by each ANTASnnn address space.
An ANTASnnn address space will use approximately 1.7 GB for an XRC session. The minimum virtual storage usage will be 200 MB + (60 KB * TotalBuffers). The maximum will be up to the amount of virtual storage available on the system below the 64-bit bar. The exact amount of storage used depends on the number of storage control sessions and the amount of data being moved. If more than 1.7 GB is required, it is recommended that additional Coupled/Clustered XRC sessions be used.
Ensure that local paging space on the SDM is sufficient to support your planned remote copy configuration.
XRC needs a minimal amount of space (0.2 KB) in the extended common service area (ECSA). All other storage used is within the XRC address spaces. The ANTCLnnn address space requires a minimum of 182 KB of extended common service area (ECSA).
XRC supports a maximum of 80 storage control sessions for each XRC session.