DEV007 | 019C | RW | 0 | 0 | RW | 0018 | WD | 0 | 0 | A..X | Consistent |
DEV007 | 019D | RW | 0 | 0 | RW | 0019 | WD | 0 | 0 | A..X | Consistent |
Package Configuration using SRDF/Synchronous or SRDF/Asynchronous
The following describes configuring a package using SRDF/Synchronous or SRDF/Asynchronous MSC for
If this is a
1.Copy the template file that is shipped with the Metrocluster with EMC SRDF product from
/opt/cmcluster/toolkit/SGSRDF/srdf.env to the package directory.
2.Customize the template file based on the requirements in your environment.
If there is a
•Set new variable RDF_MODE to sync
RDF_MODE=sync
If RDF_MODE is not present, the synchronous mode is assumed.
•Unset the SYMCLI_MODE environment variable if it has been set previously.
Migration of Existing Applications from SRDF/Synchronous to SRDF/Asynchronous
EMC does not support migration on the existing applications from SRDF/Synchronous to SRDF/Asynchronous data replication. Applications that need to use SRDF/Asynchronous mode for data replication should configure a new device group in SRDF/Asynchronous mode. The need to alter the data replication mode between synchronous and asynchronous for an application is not expected in a typical Disaster Tolerant environment. Contact EMC and HP for specific requirement to your environment.
Package Failover using SRDF/Asynchronous
The EMC Solutions Enabler provides a control operation checkpoint to confirm that the data written in the current SRDF/Asynchronous cycle has been successfully committed to the R2 side. When a package fails over to secondary site, Metrocluster with EMC SRDF ensures the most current data when the SRDF link is still up. Metrocluster with EMC SRDF will invoke the action checkpoint prior to fail over to the storage. Since the checkpoint operation will prolong the failover time for a package to start, the duration for a package to start on R2 side will be longer. The time taken to complete the checkpoint operation depends on the cycle time configured which determines the amount of data outstanding on the R1 site.
Protecting against a Rolling Disaster
It is recommended to use the procedure described in the previous section for protecting against rolling disaster situation.
Limitations and Restrictions
•Consistency Group with SRDF/Asynchronous mode is not supported.
•Domino mode is not supported in SRDF/Asynchronous mode.
•Metrocluster with ECM SRDF does not support cascading configuration using SRDF/Asynchronous.
294 Building Disaster Recovery Serviceguard Solutions Using Metrocluster with EMC SRDF