On Wed, Jun 18, 2014 at 2:46 PM, <m.roth at 5-cent.us> wrote: > Digimer wrote: > > On 18/06/14 12:32 PM, Alessandro Baggi wrote: > >> Ok, fencing is a requirement for a cluster for hardware failure. > >> I've another question about this arg, but for software failure. > >> Supposing to have a cluster of httpd installation on 6 virtualized > >> hosts, each one on a different server. Suppose also that a guest (named > >> host6) has a problem and can't start apache. With this scenario, the > >> ipmi, ups are unnecessary. How to work fencing in this way? How to make > >> fencing node? > >> > > I'm not sure I understand properly... You mean that you have 6 VMs which > > are nodes in a cluster, or 6 nodes, each hosting a VM you want to make > HA? > <snip> > I'm not clear on what you mean, either. Is this supposed to be a > load-balancing cluster? If so, and you expect that kind of load, I, > My interpretation mirrors Mark's ... sounds like you want to load balance between the six servers. If so, you might create a proxy with haproxy [0] [1] that will relegate connections to each of your six nodes. [0] http://haproxy.1wt.eu/download/1.4/doc/configuration.txt [1] http://www.rackspace.com/knowledge_center/article/setting-up-haproxy > personally, would *never* put a VM on them - I'd want the full resources > of the o/s brought to bear on that load, and use multiple real hardware > Makes sense in the terms of hardware redundancy, but if it's OS level redundancy then this could fly. _BUT_ it isn't as ideal as having separate hardware. If Alessandro's VMs are clustered between a pair of nodes with shared/replicated storage, then I'd say it is a realistic scenario. Layered redundancy for the win! (akin to layered security) Rackspace has haproxy as part of their cloud offerings [2]. Albeit likely resources not on the same single piece of hardware! > for the other members. Doing this with VMs is only multi-threading the > load, and adding more, with all the context switches. > > mark > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > -- ---~~.~~--- Mike // SilverTip257 //