Forum Discussion

Zahid_Haseeb's avatar
Zahid_Haseeb
Moderator
7 years ago

Can we us heartbeat NIC to connect with a IP device ?

Suppose a 2 nodes VCS HA environment have 2 local heartbeats. As per my understanding VCS dont need IP addresses for its local heartbeats communication and uses its own protocol(LLT) for heartbeats between both HA nodes.
My question is, if we assign an IP address on one heartbeat NIC and connect a ip device back to back, Can we allow to do it ?

  • Hello,

    Technically yes you can do it although it is not recommended for a failover VCS configuration.

    As Veritas cluster requires minimum two dedicated NICs for cluster inter node heartbeat (primarily) communicaton on dedicated private network meaning if an IP is plumbed on a private NIC, only the nodes in the cluster can use this IP for sending/receiving network packets.  For testing purpose, its perfectly OK to plumb an IP on one or both NICs.

    However if you think of transmiting large amount of data through these NICs via LLT private network, it is not recommended.  When the large amount of packets is transmitted through the LLT network, it may results cluster nodes miss heartbeat and errors like node inactive/in trouble may be resulted.

    For CVM/CFS/RAC clusters, they are different and beyond the scope of this discussion.

    Regards,

    Frank

    • Zahid_Haseeb's avatar
      Zahid_Haseeb
      Moderator

      Actually we have four NICs and all are occupied. Any recommandation if we can go with a low priority heartbeat with single LLT heartbeat ?

      • CliffordB's avatar
        CliffordB
        Level 4
        The absolute minimum is one private and one (low priority) public.

        But, I would not bet my paycheck on such a configuration. As others have said, two private links, using different NIC cards and switch infrastructure, along with one or more low-propriety (public) links, are what is recommended for production. The cost of NICs and switch ports are very small compared to time spent troubleshooting an unstable cluster and associated downtime. The above recommendation is for ANY cluster technology, not just VCS.

        I suggest reading the Admin Guide and refer to the sections that mention failure scenarios and how the cluster behaves when down to one communications path (jeopardy).

        Cheers