IN THIS ARTICLE
- Outlines how to enable IP Failover in the Qumulo Core Web UI and via CLI.
- Command line (CLI) tools installed via API & Tools tab
IP Failover is a high-availability feature that allows a cluster node's virtual IP address(es) to be reassigned to other nodes in the cluster should a node become offline for any reason.
In addition to the fixed IP range assigned to a cluster, an administrator can set a "floating" range of addresses that can be reshuffled amongst online nodes as necessary. When using IP Failover, it is recommended that the cluster's client-facing DNS record be pointed at these floating IPs, as opposed to the fixed range. For example, in a BIND zone, your records may look something like this (where 10.101.1.201-204 is the floating range):
Clients mount the cluster using the 'qumulo' hostname, for example:
mount -t nfs -o rsize=524288,wsize=524288 qumulo:/production/ /production
In a node outage scenario, any IP in the floating range that was assigned to the offline node would move to another available node, ensuring that connected clients can continue writing and reading to/from the cluster. Typically the time to fail an IP over to another node will cause only a momentary blip in any running workloads. Please note that stateful connections such as SMB will have to re-connect, as they require a new TCP connection. However, the failover is fast enough that most operating system's retry mechanism can handle it. To set up IP Failover on your Qumulo cluster, you can use the Qumulo Core Web UI, or configure via CLI. Instructions for both methods are below.
- Log in to your cluster's Web UI as 'admin', hover over the Cluster menu and click on Network Configuration.
- On the Network Configuration page, click on Edit Static Settings.
- In the fields for Persistent IPv4 Addresses and Floating IPv4 Addresses, enter your fixed and floating ranges, then click save.
- First ssh to a cluster node as admin
- Now become root
- Lastly replace the IP range in this example with the floating range you want
qq network_conf_mod --floating-ip-ranges 10.100.1.201-204
Note: For floating IPs, we recommend assigning N-1 virtual IPs (where N is the total # of nodes in the cluster). Assuming many client connections, this could help evenly distribute the connections from the lost node on to the remaining nodes. For example, in a 4 node cluster, if 1 node goes offline, its 3 virtual IPs would then float to each of the remaining 3 nodes.
You should now be able to successfully set up IP failover on your Qumulo Cluster via the web UI or CLI.
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