7.4 HA 4.7.2 Enhancements

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PowerHA now includes several additional enhancements including:

• The recently announced reduced data transfer during resynchronization with Geographic Mirroring Compression is now available.

• The Spectrum Virtualize (SVC) based FlashCopy automation integrated into PowerHA now includes additional automation at the target system of Geographic Mirroring, eliminating the need to manually suspend or detach the geographic mirroring replication as part of the FlashCopy process.

Reduced Data Transfer with Geographic Mirroring Compression 7.5 HA 5.1.2 7.4 HA 4.7.2

Geographic mirroring performs disk-level replication. This means that all changes on disk in an Independent Auxiliary Storage Pool (IASP) are replicated over the TCP/IP network to the target system. When PowerHA performs a synchronization, either for the initial synchronization, after an unplanned failure, or when resuming from a suspend operation, PowerHA replicates data over the TCP/IP network.

With this enhancement, PowerHA can now compress geographic mirroring data during resynchronization reducing the data transfer required. In addition, on Power10 systems, PowerHA uses the on-chip NX GZIP accelerator if the NX feature is enabled, providing hardware accelerated compression.

Enabling Geographic Mirroring Compression

With new environments, transmission compression can be enabled on the Configure Geographic Mirroring (CFGGEOMIR) command by specifying *RESYNC for the transmission compression attribute. For example, when configuring asynchronous geographic mirroring for the IASP, MYIASP, the following command enables geographic mirroring compression:

CFGGEOMIR ASPDEV(MYIASP) ACTION(*CREATE) DELIVERY(*ASYNC) COMPRESS(*RESYNC)

In existing environments, geographic mirroring compression can be enabled by changing the transmission compression attribute on the auxiliary storage pool session. For example, the following command enables compression for the session named GEOMIRSSN:

CHGASPSSN SSN(GEOMIRSSN) OPTION(*CHGATTR) COMPRESS(*RESYNC)

Determining if Geographic Mirroring Compression is Enabled

The following interfaces provide information to determine if transmission compression is enabled:

• The QHASM.SESSION_INFO table function SQL service is enhanced with a new TRANSMISSION_COMPRESSION field.

• The Display ASP Session (DSPASPSSN) display and print panels are enhanced with a new transmission compression field.

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Geographic Mirroring FlashCopy Automation 7.5 HA 5.1.2 7.4 HA 4.7.2 7.2 HA 3.9

The Spectrum Virtualize (SVC) based FlashCopy automation integrated into PowerHA now includes additional automation at the target system of Geographic Mirroring, eliminating the need to manually suspend or detach the geographic mirroring replication as part of the FlashCopy process.

The following operations are now automated:

• SVC FlashCopy verifies the replication state if the FlashCopy is at the target side of geographic mirroring replication and prompts the user to confirm if replication is not active.

• If replication is at the target of geographic mirroring, the replication is automatically suspended at the appropriate point during the FlashCopy process, and automatically resumed, with as little impact on the recovery point objective (RPO) as possible.

• The ability to automatically quiesce the production copy when performing a FlashCopy operation using the source ASP Action (SRCASPACN) parameter.

• The target ASP Action (TGTASPACN) parameter provides support for automatically varying on a FlashCopy target ASP.

Enhancement Availability