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What is cluster UUID (Universally Unique ID) and how it works.

Article: 100002260
Last Published: 2018-04-23
Ratings: 0 0
Product(s): InfoScale & Storage Foundation

Problem

This document explains what a cluster UUID (Universally Unique ID) is and how it works.

Solution

What is cluster UUID (Universally Unique ID) and how it works.
 

 
Description :
 
From Storage Foundation 5.1 onwards, Cluster UUID concept has been introduced.
 
When VCS is installed using the installer, the installer generates the cluster UUID (Universally Unique ID) value. This value is the same across all the nodes in the cluster.
 
Use the uuidconfig utility to display, copy, configure, and unconfigure the cluster UUID (universally unique id) on the cluster nodes.
 
Make sure that ssh or rsh communication is set up between the systems. The utility uses ssh by default.
 

 
To display the cluster UUID value on the VCS nodes
 
Run the following command to display the cluster UUID value: For specific nodes:
 
# /opt/VRTSvcs/bin/uuidconfig.pl [-rsh] -clus -display sys1 [sys2 sys3...]
 

 
For all nodes that are specified in the /etc/llthosts file:
 
# /opt/VRTSvcs/bin/uuidconfig.pl -display -clus -use_llthost
 

 
Example :
 
# /opt/VRTSvcs/bin/uuidconfig.pl -clus -display node100 (Individual node)
 
Finding existing UUID information ...
 
node100 .... exist.
 
Done
 
Valid uuid exist on node100
 
{6a2237be-1dd2-11b2-bb6e-58486d0040ad} : node100
 

 
For all nodes that are specified in the /etc/llthosts file:
 
# /opt/VRTSvcs/bin/uuidconfig.pl -clus -display -use_llthost (Cluster)
 
Finding existing UUID information ...
 
node100 .... exist.
 
node200 .... exist.
 
Done
 
Valid uuid exist on node100 node200
 
{6a2237be-1dd2-11b2-bb6e-58486d0040ad} : node100 node200
 

 
To configure cluster UUID on the VCS nodes
 
Run the following command to configure the cluster UUID value: For specific nodes:
 
# /opt/VRTSvcs/bin/uuidconfig.pl [-rsh] -clus -configure sys1 [sys2 sys3...]
 

 
For all nodes that are specified in the /etc/llthosts file:
 
# /opt/VRTSvcs/bin/uuidconfig.pl -clus -configure -use_llthost
 

 
The utility configures the cluster UUID on the cluster nodes based on whether a cluster UUID exists on any of the VCS nodes:
 
- If no cluster UUID exists or if the cluster UUID is different on the cluster nodes then the utility:
 
- Generates a new cluster UUID using the /opt/VRTSvcs/bin/osuuid.
 
- Creates the /etc/vx/.uuids/clusuuid file where the utility stores the cluster UUID.
 
- Configures the cluster UUID on all nodes in the cluster.
 

 
- If a cluster UUID exists and if the UUID is same on all the nodes, then the utility retains the UUID.
 
Use the -force option to discard the existing cluster UUID and create new cluster UUID.
 

 
- If some nodes in the cluster have cluster UUID and if the UUID is the same, then the utility configures the existing UUID on the remaining nodes.
 

 
To unconfigure cluster UUID on the VCS nodes
 
Run the following command to unconfigure the cluster UUID value:For specific nodes:
 
# /opt/VRTSvcs/bin/uuidconfig.pl [-rsh] -clus -unconfigure sys1 [sys2 sys3...]
 

 
For all nodes that are specified in the /etc/llthosts file:
 
# /opt/VRTSvcs/bin/uuidconfig.pl [-rsh] -clus -unconfigure -use_llthost
 

 
The utility removes the /etc/vx/.uuids/clusuuid file from the nodes.
 

 
To copy the cluster UUID from one node to other nodes
 
Run the following command to copy the cluster UUID value:
 
# /opt/VRTSvcs/bin/uuidconfig.pl [-rsh] -clus -copy -from_sys sys -to_sys sys1 sys2 [sys3...]
 

 

The utility copies the cluster UUID from a system that is specified using the -from_sys option to all the systems that are specified using the -to_sys option.
 

 
 

 

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