Create a directory /etc/cmcluster/pkgname for each package:
# mkdir /etc/cmcluster/pkgname
Create a package configuration file with the commands:
# cd /etc/cmcluster/pkgname
# cmmakepkg -p pkgname.ascii
Customize the package configuration file as appropriate to
your application. Be sure to include the pathname of the control
script (/etc/cmcluster/pkgname/pkgname.cntl) for the RUN_SCRIPT and HALT_SCRIPT parameters.
In the <pkgname>.ascii file, list the node names in the order in which you
want the package to fail over. It is recommended for performance
reasons, that you have the package fail over locally first, then
to the remote data center.
 |
| |
|
 | NOTE: If you are using the EMS disk monitor as a package resource,
you must not use NO_TIMEOUT. Otherwise, package shutdown will hang if there
is not access from the host to the package disks. |
|
| |
|
This toolkit may increase package startup time by 5 minutes
or more. Packages with many disk devices will take longer to start
up than those with fewer devices due to the time needed to get device status
from the EMC Symmetrix disk array. Clusters with multiple packages
that use devices on the EMC Symmetrix disk array will cause package
startup time to increase when more than one package is starting
at the same time.
The value of RUN_SCRIPT_TIMEOUT in
the package ASCII file should be set to NO_TIMEOUT or
to a large enough value to take into consideration the extra startup
time due to getting status from the Symmetrix.
Create a package control script with the command:
# cmmakepkg -s pkgname.cntl
Customize the control script as appropriate to your application
using the guidelines in Managing MC/ServiceGuard. Standard MC/ServiceGuard
package customizations include modifying the VG, LV, FS, IP, SUBNET, SERVICE_NAME, SERVICE_CMD and SERVICE_RESTART parameters.
Be sure to set LV_UMOUNT_COUNT to 1 or greater.
Add customer-defined run and halt commands in the
appropriate places according to the needs of the application. See Managing MC/ServiceGuard for
more information on these functions.
In the package_name.ascii file, list the node names in the order in which you
want the package to fail over. It is recommended for performance
reasons, that you have the package fail over locally first, then
to the remote data center. Be sure to set the MAX_CONFIGURED_PACKAGES parameter to 1 or more, depending on the number
of packages that will run on the cluster.
Copy the environment file template /opt/cmcluster/toolkit/SGSRDF/srdf.env to the package directory, naming it pkgname_srdf.env:
# cp /opt/cmcluster/toolkit/SGSRDF/srdf.env \
/etc/cmcluster/pkgname/pkgname_srdf.env
Edit the environment file <pkgname>_srdf.env as follows:
Add the path where the srdf.env SymCLI
software binaries have been installed to the PATH environment
variable. If the software is in the usual location, /usr/symcli/bin, you can just uncomment the line in the script.
Uncomment AUTO*environment
variables. It is recommended that you retain the default values
of these variables unless you have a specific business requirement
to change them. See Appendix B for an explanation of these variables.
Uncomment the PKGDIR variable
and set it to the full path name of the directory where the control
script has been placed. This directory must be unique for each package
and is used for status data files. For example, set PKGDIR to /etc/cmcluster/package_name, removing any quotes around the file names.
Uncomment the DEVICE_GROUP variables EMC Symmetrix for the local disk array
and set it to the Symmetrix device group names given in the symdg list command. If you are using an M by N configuration, configure
the DEVICE_GROUP variable with the name of the consistency group.
Uncomment the RETRY and RETRYTIME variables.
These variables are used to decide how often and how many times
to retry the Symmetrix status commands. The defaults should be used
for the first package. For other packages RETRYTIME should
be altered to avoid contention when more than one package is starting
on a node. RETRY * RETRYTIME should
be approximately five minutes to keep package startup time under
5 minutes.
| | RETRYTIME | RETRY |
|---|
| pkgA | 60 seconds | 5 attempts |
| pkgB | 43 seconds | 7 attempts |
| pkgC | 33 seconds | 9 attempts |
Uncomment the CLUSTERTYPE variable
and set it to METRO. (The value CONTINENTAL is only for use with the ContinentalClusters product,
described in Chapter 5.)
If you are using an M by N configuration, be sure
that the variable CONSISTENCYGROUPS is set to 1 in the control script:
CONSISTENCYGROUPS=1
Distribute
MetroCluster/SRDF configuration, environment and control script
files to other nodes in the cluster by using ftp or rcp:
# rcp -p /etc/cmcluster/pkgname/* \
other_node:/etc/cmcluster/pkgname
See the example script Samples/ftpit to see how to semi-automate the copy using ftp. This script assumes the package directories already
exist on all nodes.
Using ftp may be preferable at your organization, since it does
not require the use of a.rhosts file for root. Root access via .rhosts may create a security issue.
Verify that each node in the MC/ServiceGuard cluster
has the following files in the directory /etc/cmcluster/pkgname:
- pkgname.cntl
ServiceGuard package control
script
- pkgname_srdf.env
MetroCluster/SRDF environment
file
- pkgname.ascii
ServiceGuard package ASCII
configuration file
- pkgname.sh
Package monitor shell script,
if applicable
- other files
Any other scripts you use
to manage MC/ServiceGuard packages
The MC/ServiceGuard cluster is ready to automatically switch packages
to nodes in remote data centers using MetroClusters/SRDF
Check the configuration using the cmcheckconf -P package_name.ascii, then apply the MC/ServiceGuard configuration using the cmapplyconf -P package_name.ascii command or SAM.
Restore
the SRDF logical links for the disks associated with the application
package. See the script Samples/post.cmapply for an example of how to automate this task. The script
must be customized with the Symmetrix device group names. You may
want to redirect the output of this script to a file for debugging
purposes.
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