Role of HDDs in InterWorx Cluster nodes (?)

[john2k]

With interworx clustering it's my understanding that all the nodes mount the /home directory of the cluster manager.

So, with all site data remaining on the cluster manager, what is the role of hard disk drives in cluster nodes? Do the node hard drives perform any function for the cluster other than containing the OS and InterWorx install for that node?

Do the node hard drives maintain any sort of cached copy of the data in /home on the cluster manager?

What I'm trying to accomplish with this info is determine what capacity and speed HDD would be required for the nodes.

Would using small and relatively slow HDDs on the nodes have any effect on the performance of the cluster?

Is there any sort of minimum capacity required for the node HDDs beyond the space that is needed for the OS & InterWorx?

[IWorx-Paul]

With interworx clustering it's my understanding that all the nodes mount the /home directory of the cluster manager.

So, with all site data remaining on the cluster manager, what is the role of hard disk drives in cluster nodes? Do the node hard drives perform any function for the cluster other than containing the OS and InterWorx install for that node?

In addition to what you mentioned, the node hard drive holds the web transfer and error logs for the node in question, which are then mounted by the CM over NFS for inclusion when calculating statistics. But that is about it.

Do the node hard drives maintain any sort of cached copy of the data in /home on the cluster manager?

No, they currently do not.

What I'm trying to accomplish with this info is determine what capacity and speed HDD would be required for the nodes.

Would using small and relatively slow HDDs on the nodes have any effect on the performance of the cluster?

The only thing to take into account is what I mentioned above, the web logs for the nodes are stored on those drives. They logs are rotated away daily after daily statistics are calculated from them.

Is there any sort of minimum capacity required for the node HDDs beyond the space that is needed for the OS & InterWorx?

No, no minimum, you just want to be able to cover the log files, which will vary depending on the traffic of the websites so there's no hard and fast rule.

Paul