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Serviceguard Continentalcluster with EMC SRDF–DR Testing


Serviceguard Continentalcluster with EMC SRDF–DR Testing

Hi all,

We are having continental cluster with SRDF configuration. This week-end we are doing DR test for this application.

Stop application packages on PROD site. Bring the DR packages up on DR site and test the application. Then shutdown DR package and start prod package on PROD site.

Here is my issue:

During this test we don’t want to bring the DR site data changes to PROD site. If I used “cmrecovercl” command to fail-over, it will promote R1 Side as R2 and R2 side as R1. When I fail-back it will copy data from DR site to PROD site.

To avoid this Can I follow these steps?

1. Stop packages in PROD site. Using cmhalt package command.
2. Sync. SRDF data from PROD to DR site, after Sync completed split the SRDF link.
3. Start the package in DR site using cmrunpkg command.
4. Test the application.
5. After test is completed stop the packages in DR site using cmhalt command.
6. Establish the SRDF link.
7. Start the packages in PROD site using cmrunpackage command.

Do you see any problem doing this? If SRDF link is in split mode, Is it possible to start the packages in DR site?


Stephen Doud
Honored Contributor

Re: Serviceguard Continentalcluster with EMC SRDF–DR Testing

1) halt the cluster on the primary site
2) interrupt the SRDF links(note that splitting the EMC's resulting in a
R1=rw, R2=rw, split state is an unsupported configuration and the package
cannot start in this mode)
3) To enable the DR package to start at the R2 site, set the
following parameters in /etc/cmcluster//srdf.env
There is no need to run a cmapplyconf after making this change.
Since we're starting on the R2 site, with the link down:
if Array state = W-Disabled, set AUTOR2RWNL=0 (ignores data currency
if Array state = ReadWrite, set AUTOR2WDNL=0 (ignores data currency

4) Start the DR recovery on the recovery cluster (pg 161 of the
# cmrecovercl
Note this should automatically start the packages if things are configured
properly. There should be no need for the 'cmforceconcl cmrunpkg ...' command.
5) After the DR package startup and data manipulation test is completed,
perform a package failback:
# cmhaltpkg
# cmhaltpkg ccmonpkg on DR cluster

6) Set R2 to Write-disabled if not already set.
7) Restore the links between R1 and R2 & sync data from R1 to R2
8) Start production package on primary site and server.
9) restart ccmonpkg at the DR cluster.