Changing IP Addresses

To change IP addresses on a cluster, generate a configuration file of the currently state of the nodes with their current IP addresses, edit the file to change one or more IP addresses as desired, re-load the file, and trigger the head node to recompute the new addresses and update the database. For example:

cw-cluster-conf save new_cluster.conf
# manually edit new_cluster.conf to change IP addresses
cw-cluster-conf load new_cluster.conf
cw-nodectl -i <NODES_THAT_CHANGE> update ip=

The new addresses are not seen by compute nodes until they reboot or perform a dhcp renewal.

Each compute node should have a unique hardware product UUID. In rare cases, different nodes can end up with a common UUID. This can occur when a compute node is down and you change the IP address on another node. Having duplicate node UUIDs is not likely to impact cluster functionality, but could result in a problem if you change to IPv6 IPs given out via DHCPv6. You can review node UUIDs by running:

cw-nodectl --fields hardware.product_uuid ls -l