feedback on GDPS/PPRC experience

[lchiu7]

Hi

Currently involved in a situation where the primary mainframe site has SAN replication across to a secondary site using TPC-R. The distance is about 75km and we use 8Gps DWDM fibre to make the connection.

This gives us about a 4 hour RTO for DR.

Questions are being asked if we can do better given our investment in the fibre connection and current replication.

Digging around on IBM Red Books etc. GDPS/PPRC has come up as an option.

This is a relevant publication

https://www.redbooks.ibm.com/redbooks/pdfs/sg246374.pdf


The idea is we would run a Sysplex across the two sites but keep all the workload on the primary site and just use the secondary site LPAR (something small like a 50mips LPAR) to act as the coordinator for the replication.

The workload is mainly CICS/DB2 with some VSAM files.

It's not clear reading this Red book if PPRC can do all the replication for us or we need specif products like
InfoSphere Data Replication for IMS for z/OS
InfoSphere Data Replication for VSAM for z/OS
InfoSphere Data Replication for DB2 for z/OS

for each subsystem.

Any ideas would be really helpful?

Thanks

[Anuj Dhawan]

This is not my area but curiosity kills. I have searched and got a pdf which might be relevant - please see the table at page 169, that gives some direction, hopefully:

https://www.redbooks.ibm.com/redbooks/pdfs/sg246547.pdf

I might be badly off the mark, though.

[lchiu7]

It's a complex area it seems. Got in touch with the experts at the Washington Systems Center and it appears that we can do hardware based replication using GDPS Metro Mirror (which is based on Copy Services Manager and Hyperswap) and have a RPO of 0. But we cannot run Active-Active because that is limited to 20km because of Coupling Facility latency issues. I think we can live with that since we will run Active-Passive with the second site LPARs all powered off and only initiated during a DR event. A small local LPAR (K-SYS) can do that automatically with GDPS

[Anuj Dhawan]

Thanks and appreciate sharing what you choose as solution.