Frequently asked questions (FAQs)
If you have questions about the GDR solution, review the following list of answers to some frequently asked questions.
- How many sites can be configured by using the GDR solution?
- Currently, only two sites can be configured. An active site and a backup site.
- Which POWER® servers can be included for disaster recovery by using the GDR solution?
- POWER7® processor-based server, or later.
- Which type of storage devices are supported by the GDR solution?
- EMC Symmetrix Remote Data Facility (SRDF) capable systems: Both SRDF/A (Asynchronous) and SRDF/S (Synchronous) replication modes are supported.
- SAN Volume Controller (SVC) system and Storwize® system: Both the Metro Mirror (synchronous) and the Global Mirror (asynchronous) modes of data replication are supported.
- DS8000® storage system: Only Global Mirror (asynchronous) mode of data replication is supported.
Hitachi storage systems: Only asynchronous mode of storage replication is
supported.
Note: The SVC, Storwize, and DS8000 storage systems are supported only with VIOS Version 2.2.5.20, or later and HMC Version 8 Release 8.6.0 Service Pack 1, or later. The Hitachi storage systems are supported with VIOS Version 2.2.6.00, or later and HMC Version 9 Release 9.1.0, or later.- Does this solution support Shared Storage Pool (SSP)?
- Yes. The GDR
solution also supports shared storage configuration. For more information, see Managing the shared storage configuration.
- Does the GDR solution support any flexible capacity management solutions?
- Yes. The GDR solution supports
Enterprise Pool Capacity on Demand (CoD) and Elastic CoD (formerly known as On/Off CoD) features.
The GDR solution manages the memory and
processor requests before starting the disaster recovery operation. For more information, see Managing the CoD resources. The GDR solution also supports flexible capacity
policies by using the KSYS command interface. For more information, see Configuring the flexible capacity policies.
- Which operation systems are supported for the virtual machines in the hosts?
- AIX® Version 6.1, and later
- PowerLinux™ (Red Hat, SUSE, and Ubuntu Linux distributions)
- IBM® i Version 7.2, and later
See Requirements for the GDR solution for more information.
- Can the GDR solution work in the presence of other high availability and disaster recovery solutions in the current environment?
- Yes, if the cluster management of the virtual machines that are covered under other high availability and disaster recovery solutions are handled separately and outside of the KSYS subsystem. A specific virtual machine can be included in only one high availability and disaster recovery solution.
- What is the minimum version of HMC that must be used for this solution?
- See Requirements for the GDR solution.
- What is the minimum version of VIOS that must be used for this solution?
- See Requirements for the GDR solution.
- What is KSYS?
- The KSYS (also known as controlling system) is a controlling software for the disaster recovery operation that operates in an AIX Version 7.2.1 (or later) logical partition in the backup site and controls the entire cloud environment for the GDR solution. The KSYS is responsible for carrying out recovery actions if a disaster or a potential disaster occurs.
- Can I test the disaster recovery operation without an actual disaster?
- Yes. The GDR solution performs
failover rehearsal at the backup site in the disaster recovery environment, without disrupting the
production workloads or the storage replication from the active site to the backup site. For more
information, see Failover rehearsal of the disaster recovery operation.