There are two
reasons for expanding system capacity: to be able to handle more simultaneous
calls and to increase the retention period of your recordings.
If your goal is to
handle more calls, then you can add nodes to your cluster. Each node adds both
simultaneous activity capacity (the ability to perform more parallel recording,
monitoring, download, and playback activities) and storage capacity. Servers
may be added to a cluster at any time, but there is no ability to remove
servers from a cluster.
Once your cluster
has reached its maximum size (5 nodes for 7 vCPU systems, 2 nodes for
everything else), your only option is to add a new cluster. If you do, you must
arrange your clusters with approximately equal numbers of nodes. If that is not
possible, then you should at least arrange the call distribution so that an
approximately equal number of calls is directed to each cluster, possibly
leaving the larger cluster underutilized. For more information, see
Very Large Deployments.
There is no
capability to remove a node from a cluster once it has been added.
If your intention
is to achieve a longer retention period for your recordings, you have two
options. You can add nodes, as described above, or you can provision more
storage space per node. Each node can handle up to 12 TB of recording storage
provided that the underlying hardware can support it. UCS-B/C servers with SAN
can handle the storage capacity easily, but servers using direct attached
storage (DAS) and low-end UCS-E servers are more limited.
As with nodes in a
cluster, there is no capability to remove storage capacity from a node once it
has been installed.