Discovery Mechanisms

Typically, the choice of discovery mechanism depends on the Network Topology in your setup. Depending on the value of discovery_mechanism in input/provision_config.yml, potential target servers can be discovered one of four ways:

switch_based

Omnia can query known switches (by SNMPv3 username/password) for information on target node MAC IDs.

Pros

  • The whole discovery process is totally automatic.

  • Admin IP, BMC IP and Infiniband IP address configuration is automatic on the target nodes.

  • Re-provisioning of servers will be automatic.

  • PXE booting servers is supported via split ports on the switch.

Cons

  • Users need to enable IPMI on target servers.

  • Servers require a manual PXE boot after the first run of the provision tool

For more information regarding switch-based discovery, click here

mapping

Manually collect PXE NIC information for target servers and manually define them to Omnia using a mapping file using the below format:

pxe_mapping_file.csv

MAC,Hostname,IP

xx:yy:zz:aa:bb:cc,server,10.5.0.101

aa:bb:cc:dd:ee:ff,server2, 10.5.0.102

Pros

  • Easily customized if the user maintains a list of MAC addresses.

Cons

  • The user needs to be aware of the MAC/IP mapping required in the network.

  • Servers require a manual PXE boot if iDRAC IPs are not configured.

For more information regarding mapping files, click here

bmc

Omnia can also discover nodes via their iDRAC using IPMI.

Pros

  • Discovery and provisioning of servers is automatic.

  • Admin, BMC and Infiniband IP address configuration is automatic on the control plane.

  • LOM architecture is supported (including cloud enclosures: C6420, C6520, C6620).

Cons

  • For iDRACs that are not DHCP enabled (ie Static), users need to enable IPMI manually.

For more information regarding BMC, click here

snmpwalk

Omnia can query known switches (by IP and community string) for information on target node MAC IDs.

Pros
  • The method can be applied to large clusters.

  • User intervention is minimal.

Cons
  • Switches should be SNMP enabled.

  • Servers require a manual PXE boot if iDRAC IPs are not configured.

  • PXE NIC ranges should contain IPs that are double the iDRACs present (as NIC and iDRAC MACs may need to be mapped).

  • LOM architecture is not supported (including cloud enclosures: C6420, C6520, C6620).

For more information regarding snmpwalk, click here

If you have any feedback about Omnia documentation, please reach out at omnia.readme@dell.com.