NVP‑vProxy: Appliance Shows Unavailable and Fails to Process Backup Work Orders

The NVP integration uses a vProxy appliance to perform VM backups. Backups fail when they run against a specific vProxy in the environment. Other vProxy appliances may continue to function normally. The NetWorker server daemon.raw log and the NetWorker Management Console (NMC) show a warning indicating the vProxy is unavailable:

YYYY/MM/DD HH:MM:SS nsrd NSR info VM proxy Warning event: vProxy '[VPROXY_NAME]' is unavailable.

The vProxy /opt/emc/vproxy/runtime/logs/vrapid/vrapid-engine.log shows continuous errors indicating the AMQP connection to the local RabbitMQ message bus is refused:

YYYY/MM/DD HH:MM:SS NOTICE: Connecting to AMQP...
YYYY/MM/DD HH:MM:SS TRACE:  Dialing "amqp://guest:guest@localhost:5672/" ...
YYYY/MM/DD HH:MM:SS ERROR:  Establish AMQP connection failed, waiting 6 sec to reconnect, error: Dial: dial tcp [::1]:5672: getsockopt: connection refused

The vProxy /opt/emc/vproxy/runtime/logs/vbackupd/vbackupd-engine.log shows the same connection refusal:

YYYY/MM/DD HH:MM:SS TRACE:  Preparing to listen for requests on the message bus.
YYYY/MM/DD HH:MM:SS TRACE:  Opening connection to message bus server "amqp://guest:guest@localhost:5672/" ...
YYYY/MM/DD HH:MM:SS ERROR:  Error from Dial: dial tcp [::1]:5672: getsockopt: connection refused

The vProxy continues to retry the AMQP connection indefinitely but never succeeds, rendering the appliance unable to receive or process backup work orders from the NetWorker server.

The vProxy RabbitMQ message bus process cannot start because it is unable to reach the Erlang Port Mapper Daemon (epmd). The epmd is a prerequisite service that RabbitMQ uses for node communication. When epmd is unreachable, the RabbitMQ process fails to initialize, and the vProxy's internal message bus becomes unavailable. Without the message bus, the vProxy cannot receive backup work orders from the NetWorker server.

This is an environmental/configuration issue, not a NetWorker or vProxy software defect. The following conditions can prevent epmd from being reachable, causing the RabbitMQ startup failure:

1. The /etc/hosts file on the vProxy appliance contains an incorrect IP address for the vProxy hostname. The epmd uses hostname resolution to bind to the correct address — an incorrect entry causes the binding to fail.

2. The DNS name resolution configured on the vProxy appliance is not functioning correctly. If the vProxy cannot resolve its own hostname, the epmd cannot start properly.

3. The RabbitMQ connection attempts use the IPv6 loopback address ([::1]). If IPv6 is disabled on the vProxy appliance, the connection to [::1]:5672 is refused because the IPv6 loopback interface is not available.

1. Validate the /etc/hosts File
   • SSH to the affected vProxy appliance.
   • Review the /etc/hosts file and confirm the vProxy hostname resolves to the correct IP address:

     cat /etc/hosts

   • If the IP address entry for the vProxy hostname is incorrect, update it to the correct IP address and save the file.
2. Resolve DNS Issues
   • Verify DNS name resolution is functioning correctly on the vProxy:

     nslookup $(hostname)

   • If the DNS lookup fails, review the DNS server configuration on the vProxy and correct any issues. Ensure the vProxy can resolve its own hostname.
3. Check and Enable IPv6
   • Check whether IPv6 is disabled on the vProxy:

     sysctl -n net.ipv6.conf.all.disable_ipv6

   • If the output is 1 (disabled), enable IPv6:

     sysctl -w net.ipv6.conf.all.disable_ipv6=0 && sysctl -w net.ipv6.conf.default.disable_ipv6=0

   • Note: IPv6 must be enabled on the vProxy appliance because the RabbitMQ message bus uses the IPv6 loopback address ([::1]) for local connections. Disabling IPv6 prevents the message bus from accepting connections.
4. Start the RabbitMQ Service
   • After resolving the underlying issue (hosts file, DNS, or IPv6), start the RabbitMQ service:

     systemctl start rabbitmq-server.service

   • Verify the service is running:

     systemctl status rabbitmq-server.service

5. Verify the vProxy Is Available
   • Check the vrapid-engine.log and confirm the AMQP connection is now established successfully — the Establish AMQP connection failed errors should stop and a successful connection message should appear.
   • In the NetWorker Management Console, verify the vProxy status changes from unavailable to available.
   • Run a test backup against the affected vProxy and confirm it completes successfully.
6. If the vProxy remains unavailable after verifying the /etc/hosts file, DNS resolution, IPv6 configuration, and restarting the RabbitMQ service, contact Dell Support for further investigation and reference this KB article.