Additional network cards to 2.0.1 cluster - recommendations?



  • Hi all,

    I need to add two extra network cards to each node in a two node 2.0.1 (i386) cluster in the very near future.  Currently there are three CARP VIPs - the LAN, WAN and DMZ interfaces.

    I hope to do the upgrade without bringing down the whole cluster.  Thinking it through, the machine that is down for hardware changes will always be the slave, obviously, so how will the master react to a slave that has additional hardware?  Secondly, these cards are identical to the cards already in place.  Is it likely that enumeration will be impacted and I will need to reassign the logical names to the interfaces?  Lastly, is it a requirement that the master and slave have identical mapping of logical interface names to driver interface names?

    Thanks,

    Simon



  • It won't matter that you're adding NICs. Just make sure you assign them the same on both boxes, configure the interfaces (IPs, etc.) on both boxes, before you add CARP IPs. It won't hurt anything if you don't (it'll just refuse to add the CARP IP on the secondary if it's out of whack), but best to do it in that order regardless.

    If you're adding the same type of NICs (same driver), keep in mind your interface numbers may shift. Such as if you have em0 through em3 right now, and add another quad port em card, the new card may be em0 through em3 and the old one em4 through em7. All depends on the slots and BIOS.



  • Thanks cmb.  Seeing as how the CARP IPs are already in place and the enumeration may be a problem, I'll schedule a full outage on the cluster.

    Regards,

    Simon



  • @sgb:

    Thanks cmb.  Seeing as how the CARP IPs are already in place and the enumeration may be a problem, I'll schedule a full outage on the cluster.

    Not necessary, I've walked people through a number of such NIC additions with no issue. Do the secondary first, see if its NIC assignments have shifted, if so reassign the NICs (there will be no adverse consequences, but to make 100% sure of that, only plug it into a test network to see how the NICs get addressed). Then you know what to expect on the primary. It would be prudent to do it at a time that is as best possible in case you take them both down for some reason.


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