Service Guard Question

[Waqar Razi]

I dont have much working experience with the service guard. I have a question in this regard. Thats actually an interview question:

You have configured a service guard and when you tried to start to package, it doesnt start. What will be the things you gonna check? How will you troubleshoot it?

Can some one give me detailed answer abt it.

[Hasan Atasoy]

hi ;


first think is cheking log files under package directory ( sg versiyon < 11.18 ) . /etc/cmcluster/
also syslog.log

Hasan

[sujit kumar singh · Accepted solution]

in the package control log you shall be able to find out the actual start sequences of the package starting as well as thaose of halting a package.
Well i would like you to refer to one if you have got a SG Cluster with you.

the steps of package start are as :
1)VG Activation.
2)Check and mount fileystems.
3)Assigning of Relocatable IP Address to the package.
4)Starting the Customer Defined Run commands.
5)Starting the services (Monitoring Scripts.
6)starting the resources that shall be monitored by the package (if defined).



The Stop/Halt of a pcakge you can see
1)Stop the services.
2)Execution of the customer defined halt commands.
3)Deassingning the Relocatabale IP address.
4)Unmount the Filesystems.
5)deactivate the VGs.


all these steps are critical and package at the start / halt goes through these sequences.

These are the potential Steps that a package must successfully pass for proper and successful start and stop.

Regards
Sujit

[sujit kumar singh]

A pacjake typically will not start if following things are there.

1)the node where you want to start th epackage is halted.
2)the VGs that are in the control file do not exist on the system.
3)you have not created the mount points for the mounting of the LVs in the package Vgs.
4)or the mount of the FS through the package is conflicting with the Filesystem parameters.
5)the IP address is not mentioned for the package.
6)Errors in the customer defined run commands.
7)Errors in starting the services.
8)errors in starting the resources to be monitored as defined in the package.


Regards
Sujit

[Waqar Razi]

Hey Sujit,

Thanks for this explanation.

Can you also please explain briefly the necessary steps in building a cluster.

[sujit kumar singh]

Hi Waqar,


can have a look at the following link, This is a helpful one.


http://thomasvogt.wordpress.com/2008/08/26/mcserviceguard-cluster-installation-on-hp-ux-1131/


Regards
Sujit