Designing Disaster Tolerant High Availability Clusters, 10th Edition, March 2003 (B7660-90013)

Environment File Variables for MetroCluster/SRDF
Appendix B 413
B Environment File Variables for
MetroCluster/SRDF
This appendix lists all MC/ServiceGuard control script variables that
have been modified or added for MetroCluster with EMC SRDF. It is
recommended that you use the default settings for most of these
variables, so exercise caution when modifying them:
AUTOR1RWNL Default: 0
This variable indicates that when the package is being
started on an R1 host, the Symmetrix is in a
Read/Write state, and the SRDF links are down, the
package will be automatically started. Although the
script cannot check the state of the Symmetrix on the
R2 side to validate conditions, the Symmetrix on the
R1 side is in a ‘normal’ state. To require operator
intervention before starting the package under these
conditions, set AUTOR1RWNL=1 and create the file
/etc/cmcluster/package_name/FORCEFLAG.
AUTOR1UIP Default: 1
This variable indicates that when the package is being
started on an R1 host and the Symmetrix is being
synchronized from the Symmetrix on the R2 side, the
package will halt unless the operator creates the
$PKGDIR/FORCEFLAG file.
The package halts because performance degradation of
the application will occur while the resynchronization
is in progress. More importantly, it is better to wait for
the resynchronization to finish to guarantee that the
data are consistent even in the case of a rolling disaster
where a second failure occurs before the first failure is
recovered from.
To always automatically start the package even when
resynchronization is in progress, set AUTOR1UIP=0.
Doing so will result in inconsistent data in case of a
rolling disaster.