|
|
Sponsored Content
Operating Systems
HP-UX
MC ServiceGaurd
Post 4927 by alwayslearningunix on Friday 3rd of August 2001 05:23:39 PM
08-03-2001
MC ServiceGuard is still at the forefront of HP-UX's high availability software, it has been developed to the point where (providing hardware behaves itself) it can provide 99.999% availability when spreading a service across two service guarded machines.
It's quite a sophisticated product, providing a double heartbeat between nodes to monitor machine availability in a cluster and has a whole host of cluster wide and node specific configurable parameters - HP's course covers 5 days. It works from the entry level A class server through to the top end Superdome, as well as on workstations (although the reasoning behind it's application there would be somewhat baffling).
The product does not pretend to create fault tolerant machines, I think fault tolerance in the strict sense of the word is something yet to be attained on servers, and the domain of the mainframe - but it does guarantee high availibilty and with most service level agreements providing for scheduled maintenence downtime a high availability cluster that is service guarded can provide a near fault tolerant environment by allowing services to be flipped from node to node as the sectrions of the cluster is worked on for maintenance.
It's a great product, I would recommend learning it. I am on the course next week
Regards.
It's quite a sophisticated product, providing a double heartbeat between nodes to monitor machine availability in a cluster and has a whole host of cluster wide and node specific configurable parameters - HP's course covers 5 days. It works from the entry level A class server through to the top end Superdome, as well as on workstations (although the reasoning behind it's application there would be somewhat baffling).
The product does not pretend to create fault tolerant machines, I think fault tolerance in the strict sense of the word is something yet to be attained on servers, and the domain of the mainframe - but it does guarantee high availibilty and with most service level agreements providing for scheduled maintenence downtime a high availability cluster that is service guarded can provide a near fault tolerant environment by allowing services to be flipped from node to node as the sectrions of the cluster is worked on for maintenance.
It's a great product, I would recommend learning it. I am on the course next week
Regards.
|
|
LEARN ABOUT DEBIAN
clusvcadm
clusvcadm(8) Red Hat Cluster Suite clusvcadm(8) NAME
clusvcadm - Cluster User Service Administration Utility SYNOPSIS
clusvcadm [-d <service> ] [-e <service> ] [-l] [-u] [-S] [-m <member> ] [-r <service> ] [-R <service> ] [-M <service> ] [-Z <service> ] [-U <service> ] [-s <service> ] [-v] DESCRIPTION
The clusvcadm command allows an administrator to enable, disable, relocate, and restart user services in a cluster. In order to perform cluster service operations, the cluster daemons must be running (and have quorum) on the member system on which the command is invoked. OPTIONS
-d <service> Stops and disables the user service named service -e <service> Enables and starts the user service named service -l Lock services in preparation for cluster shutdown. This should only be used if the administrator intends to perform a global, clus- ter wide shutdown. This prevents services from starting (but not stopping, like -Z does). Once the cluster quorum is dissolved, this state is reset. If a new instance of rgmanager boots while others are locked, the behavior is undefined. -u Unlock resource group managers. This allows services to start again. -S Display whether the resource group managers are locked or not. This can be used to verify the correct operation of the -l and -u options, but is only useful for debugging. -m <member> When used in conjunction with either the -e or -r options, this specifies the preferred target member on which to start the service. -r <service> Relocates the user service named service to another cluster member. -R <service> Restarts the user service named service on the cluster member on which it is currently running. -M <service> Use a special "migration" operation to move the user service named service to another cluster member. Currently, this is only use- ful for virtual machines. Use of migration usually requires special configuration of the local virtual machine manager in order to work correctly. -Z <service> Freezes the service named service on the cluster member on which it is currently running. This will prevent status checks of the service as well as failover in the event the node fails or rgmanager is stopped. -U <service> Unfreezes the user service named service on the cluster member on which it is currently running. This will re-enable status checks. -s <service> Stops the service named service until a member transition or until it is enabled again. -v Display version information and exit. NOTES
Executing -U (unfreeze) on a service which was frozen in the started state while the service owner is offline results in an undefined (and possibly dangerous) condition. Manually ensure all resources are clear before doing this. SEE ALSO
clustat(8) Jan 2005 clusvcadm(8)