Wednesday, September 9, 2009

Quick guide: how to manage Redhat Cluster in RHEL 5

Check cluster status


[root@ncs-db-1 ~]# clustat
Cluster Status for ncs_dbcluster @ Wed Sep 1 15:22:08 2009
Member Status: Quorate

Member Name ID Status
------ ---- ---- ------
ncs-db-n1 1 Online, Local, rgmanager
ncs-db-n2 2 Online, rgmanager

Service Name Owner (Last) State
------- ---- ----- ------ -----
service:clusvc ncs-db-n1 started


Disable cluster status
After disable, resource group shutdown and will not affect by server reboot and/or failover.


[root@ncs-db-1 ~]# clusvcadm -d clusvc
Local machine disabling service:clusvc...Success



Enable cluster status


[root@ncs-db-1 ~]# clusvcadm -e clusvc
Local machine trying to enable service:clusvc...Success
service:clusvc is now running on ncs-db-n1


Freeze cluster resource group
After freeze resource group, it will not being monitored by the cluster manager. But current resource group state will not be affected by this command.


[root@ncs-db-1 ~]# clusvcadm -Z clusvc
Local machine freezing service:clusvc...Success


Unfreeze cluster resource group


[root@ncs-db-1 ~]# clusvcadm -U clusvc
Local machine unfreezing service:clusvc...Success



Stop cluster resource group
Resource group can failover if current node due to fencing.


[root@ncs-db-1 ~]# clusvcadm -s clusvc
Local machine stopping service:clusvc...Success



Restart cluster resource group
Resource group can failover if current node due to fencing.


[root@ncs-db-1 ~]# clusvcadm -s clusvc
Local machine stopping service:clusvc...Success


Relocate resource to another member in the failover domain


[root@ncs-db-1 ~]# clusvcadm -r clusvc -m ncs-db-n2
Trying to relocate service:clusvc to ncs-db-n2...Success
service:clusvc is now running on ncs-db-n2


Other useful commands


[root@ncs-db-1 ~]# ccs_tool lsnode

Cluster name: ncs_dbcluster, config_version: 21

Nodename Votes Nodeid Fencetype
ncs-db-n1 1 1 ncs-db-1-ilo1
ncs-db-n2 1 2 ncs-db-2-ilo2



[root@ncs-db-1 ~]# cman_tool status
Version: 6.1.0
Config Version: 21
Cluster Name: ncs_cluster
Cluster Id: 27444
Cluster Member: Yes
Cluster Generation: 1796
Membership state: Cluster-Member
Nodes: 2
Expected votes: 1
Total votes: 2
Quorum: 1
Active subsystems: 9
Flags: 2node Dirty
Ports Bound: 0 11 177
Node name: ncs-db-n1
Node ID: 1
Multicast addresses: xxx.xxx.xxx.xxx
Node addresses: xxx.xxx.xxx.xxx