topic Re: Single Node ServiceGuard Cluster in Operating System - HP-UX

Single Node ServiceGuard Cluster

RW-S — Thu, 29 Jul 2010 05:07:28 GMT

Hello ServiceGuard Experts !!!
Is it possible to make a single node ServiceGuard Cluster?

There is just one hardware. No VM's.

I just want to test some ServiceGuard functionality like Application monitoring and also learn to use it.
Also I do not want to go into the intracacies of having shared-disks at this moment atleast.

Really do not want to use it for Application Failovers as of now atleast.

Re: Single Node ServiceGuard Cluster

njia_1 — Thu, 29 Jul 2010 05:23:06 GMT

Hi there

Yes you can setup one node cluster, there is no problem there.

there are few discussions already on this forum, you can search single node cluster to find them

here is one
http://forums11.itrc.hp.com/service/forums/questionanswer.do?threadId=1185124

Re: Single Node ServiceGuard Cluster

Stephen Doud — Thu, 29 Jul 2010 11:26:04 GMT

Yes. It is possible to create a 1-node cluster.
After the SG software and patch is installed,
# cd /etc/cmcluster
# cmquerycl -C cluster.config -n " to create a cluster configuration file.

If you don't plan to have any storage, you can leave the cluster.config file as-is and perform a cmapplyconf to build the cluster.
Use cmruncl to start the cluster. The only thing a package-less cluster will do is provide standby LAN failover, if any were configured in the cmapplyconf (check the comments in the cluster.config file).

If/when you decide to create a package that uses disks, you can add the LVM VG name to the cluster.config file using a VOLUME_GROUP reference and cmapplyconf the file to "clusterize" the VG.

To create a package, start with
# mkdir /etc/cmcluster/
# cd /etc/cmcluster/
# cmmakepkg -n
Then edit the pkgName.config file, uncommenting those resources that you want the package to use and add values as needed such as
vg /dev/vg02

If you plan on having the package start an application, you will likely need to reference an external start/stop script for the application in the pkgName.config file.
Add a reference to the external prescript. Example:
external_pre_script /etc/cmcluster//

Then copy the external script template and edit it:
# cp ../examples/external_script.template /etc/cmcluster//
Edit the appControl.sh to perform the application startup and shutdown functions needed at package start and stop events.

When you get to this point, add the package to the cluster:
# cmapplyconf -P

NOTE: If you have a complex startup application such as Oracle that has prebuilt start/stop functions in the Enterprise Cluster Master toolkit, don't use the external script method, but install the ECM product and use the README in it (eg. /opt/cmcluster/toolkit/oracle/README) to implement the package.

If all went properly, start the package with
# cmrunpkg

Re: Single Node ServiceGuard Cluster

Bhadresh — Thu, 29 Jul 2010 12:22:58 GMT

>>>Is it possible to make a single node ServiceGuard Cluster?
Yes, it's possible to make a single node ServicegGuard cluster.

Have a look at following to find more details about Managing Serviceguard:

http://bizsupport1.austin.hp.com/bc/docs/support/SupportManual/c02057890/c02057890.pdf

Regards,
Bhadresh