On Sat, Oct 23, 2010 at 12:23 PM, Robinson, Eric <[email protected]> wrote: >> Looks like you are mixing up physical connections >> and Corosync rings. > > I should not have mentioned DRBD at all as it confuses the question. > > Let me try it this way: > > How do I build a three-node Corosync cluster with redundant heartbeat > paths? I don't trust the switched network or the Ethernet bonding > drivers to be 100% reliable, and it is just good practice to have > multiple heartbeat paths. On my old 2-node clusters, I have three > heartbeat paths: the switched network, back-to-back links, and serial > cables.
You have to connect all cluster nodes to all redundant paths. That means that your only choice is several switched networks/VLANs > > It sounds like you are saying that to have multiple heartbeat paths on a > 3-node Corosync cluster, each heartbeat path must be through a separate > switched network or VLAN. I can see why this would be the case. Exactly. > > I was hoping that a crossover cable could be used to form a "logical" > ring between two nodes, and that I could configure two logical rings > between 3 servers. Nope. All nodes should be able to communicate to each other though all configured rings/paths, > > So really, maybe I'm not trying to build a 3-node cluster. What I'm > really trying to build are two 2-node clusters where one of the physical > servers participates in BOTH 2-node clusters. CLUSTER1 would consist of > physical servers A and C. CLUSTER2 would consist of physical servers B > and C. That's probably possible but I'm not sure. In this case you can use crossovers between A and C and B and C. BTW, your server C will have to have more resources (memory and CPU) than A and B because theoretically you can end up in a situation when node C has to run applications from node A and node B at the same time. > > So maybe what I want to know is, is it possible to run multiple > "instances" of Corosync on server C, such that it participates in two > separate clusters? I personally never done so but it should be possible, but really complicated to configure. I really don't know how to run two instances of Pacemaker on one node. > > Thanks for your patience. I had no idea this would end up being so > complicated. "3-node cluster" is much easier to say than to configure, > apparently. :-) Not at all. You just need to abandon crossovers and SLIPs and start using switched networks. > > -- > Eric Robinson > > > > Disclaimer - October 23, 2010 > This email and any files transmitted with it are confidential and intended > solely for General Linux-HA mailing list. If you are not the named addressee > you should not disseminate, distribute, copy or alter this email. Any views > or opinions presented in this email are solely those of the author and might > not represent those of Physicians' Managed Care or Physician Select > Management. Warning: Although Physicians' Managed Care or Physician Select > Management has taken reasonable precautions to ensure no viruses are present > in this email, the company cannot accept responsibility for any loss or > damage arising from the use of this email or attachments. > This disclaimer was added by Policy Patrol: http://www.policypatrol.com/ > _______________________________________________ > Linux-HA mailing list > [email protected] > http://lists.linux-ha.org/mailman/listinfo/linux-ha > See also: http://linux-ha.org/ReportingProblems > -- Serge Dubrouski. _______________________________________________ Linux-HA mailing list [email protected] http://lists.linux-ha.org/mailman/listinfo/linux-ha See also: http://linux-ha.org/ReportingProblems
