IBM Debuts GRS, A New Data Replication Service in the Cloud
November 16, 2022
If you run your IBM i workloads in the IBM Cloud, there is a new data replication offering available that could help you recover more quickly from a disaster. Dubbed Global Replication Services (GRS), the offering is only available for Power Systems Virtual Server customers running in two IBM data centers at the moment. But IBM says GRS could eventually be used with on-prem Power and FlashSystem deployments, too.
GRS, which IBM introduced in a September 22 blog post, provides asynchronous data replication for IBM i, AIX, and Linux data, as well as failover and failback mechanisms. The offering was designed to replicate a customer’s PowerVS storage volume from one IBM data center to a geographically distant IBM data center, as part of a replicated pair.
GRS is based in part on the data replication mechanism used in IBM’s Spectrum Virtualize, the software for managing IBM FlashSystem SAN arrays (and before that, the Storwize arrays), according to Tom Mathews, a distinguished engineer from IBM’s Austin lab who has worked on GRS.
“For very long time we’ve had global replication capabilities on-prem between two controllers,” Mathews tells IT Jungle. “It’s very similar. The magic here, though, was getting this to work in a multi-tenant” environment.
Multi-tenancy is important because it guarantees customers a level of storage isolation when running in IBM Cloud, Mathews says. In an on-prem Spectrum Virtualize environment, there wasn’t as much of a need for customers to conduct security validation to ensure that the secondary system has access to data when failover and failback mechanisms are put into action, he says.
But such controls are necessary in a shared multi-tenant environment in the cloud, and it took a bit of work by IBM to make it work, Mathews says. IBM built GRS on PowerVS so that it works “just like” Spectrum Virtualize does on prem,” he says.
“PowerVS is fundamentally a multi-tenant solution,” Mathews says. “You can have – I’m just making names up – Coke and Pepsi on the same systems, both doing replication. That’s why it’s significant.”
This has been the top request by PowerVS customers, says Ming Christensen, a director of product management who works out of the Austin lab.
“Customers want it,” she says. “They’ve been doing single-tenant private cloud environments for many generations. They want this enterprise capability in Power Virtual Server in a multi-tenant environment.”
While GRS may get additional capabilities over time, it provides a complete DR solution at this point in time, Mathews says. “It’s a complete solution,” he says. “We really don’t have any follow on work to do right now, except for maybe polishing a few things that we discovered late at the end. But you don’t have any extensive enhancements that we have planned.”
IBM says customers can wrap additional capabilities around GRS to provide a high availability solution. For example, since it’s a storage volume-based data replication system, it doesn’t know anything about IBM i objects, Mathews says. For application high availability, it would need to be paired with other software.
IBM is encouraging its customers to tape Technology Services (formerly Lab Services) and its business partners to build additional capabilities around GRS.
“That’s why we bring various capabilities to inject into the solution, inject into the products, so the customer can have an end-to-end solution,” Christensen says. “They can do it themselves, or work with our services or their preferred partner to put all these solutions together. And I think next year we’ll work on more . . . of an end-to-end solution.”
Currently, only two IBM Cloud data centers are supported with GRS, including DAL1 3, which is based in Dallas, Texas, and WDCO 4, which is based in Washington D.C. IBM plans on bringing GRS to more IBM Cloud data centers over time, Mathews says.
IBM recognizes that customers want to run in multiple architectures, including hybrid cloud setups that utilize servers and storage in on-prem and cloud data centers. IBM is working to accommodate those customers with GRS, but there are challenges, Mathews says.
“That’s a bit problematic because we don’t have control of their . . . storage,” he says. “We have to have complete control of the storage to do this safely and reliably, including the storage and the security elements around this storage and so forth.”
IBM is currently working to deliver cloud-native PowerVS in private cloud environments, via its Power Private Cloud as a service offering. GRS could potentially be included in that, Mathews says. “That’s something that we’re working on,” he says. “It’s not something we have right now.”