Why do I have to install I/O Express on all nodes in my cluster?

I/O Express is a device, not just a software program. The device driver must be installed on all nodes in a cluster to ensure data integrity. The installation on all nodes will not take much more time than it would on a single node. The driver must be loaded on all nodes and I/O Express must be started (with or without caching) on all nodes as well.

By installing I/O Express on all nodes, you assure that all nodes accessing a specific disk are reading the same data. Whenever data in cache is changed, this change is sent to the disk for update. Caches have to be synchronized across node boundaries, therefore I/O Express will not run if the device is not loaded on all the nodes of the cluster. This is a safety feature to avoid any possibility of data corruption.

On the nodes that you want I/O Express to cache, use the startup command:

 

              
                
                  $ @IOX_STARTUP.COM
                
              
            

 

On the nodes that you do not want I/O Express to cache use the command:

 

              
                
                  $ @IOX_STARTUP.COM "/NOAUTOMATIC"
                
              
            

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