Fredrich Maney wrote: > On Tue, Oct 20, 2009 at 8:55 AM, Tundra Slosek <ivoryring at gmail.com> wrote: >> I have not yet. Am I misunderstanding my reading of the documentation, that >> a quorum server is a single point of failure for the cluster (i.e. the >> cluster's availability won't be any higher than the quorum server's). As it >> stands, I'm a little surprised because my '4 node HA cluster' seems to be >> less tolerant of failure than a pair of 2-node clusters would seem to be - >> with one of the four nodes out of the cluster, a reboot of one of the >> remaining 3 causes the other 2 to panic and reboot. I think I understand >> that this is intentional to avoid a partition, but it really feels like '4 >> node cluster' is no more available than '3 node cluster'. If I'm going to >> add a 5th machine for no purpose other than to be the quorum server, would I >> be better off making the 5th machine a 5th node? > > The QS is a very light weight process (about on par with NTP) that can > run on pretty much any other server outside of the cluster nodes with > no impact. It can also be used as the QS for multiple clusters. Also, > if you are truly worried about it being a SPoF, you could have more > than one of them on different machines - or even an HA clustered QS. > Though that would probably be taking things a bit far. > >> My current experiment, which I'm working on setting up, is to have the >> Private Interconnect occur over physical NICs that are not shared for any >> other purpose. If that doesn't work, I'll try a quorum server. Either way, >> I'll keep this thread updated as I go. > > Unless you are using VLAN tagging, you are required to use dedicated > NICs for the Interconnect. >
That's true for SC 3.2, but OHAC 2009.06 allows you to use VNICs over shared physical NICs for the private interconnect. Thanks, Nick
