Greetings, On 3/1/11, Parvez Shaikh <parvez.h.shaikh@xxxxxxxxx> wrote: > Hi Ryan, > > > What is recommended method to deal with blade center fencing failure in > this situation? Do I have to add another level of fencing(between blade > center and manual) which can fence automatically(not requiring manual > interference)? > IIRC, I had touched upon similar fencing post some time back. AFAIK, Manual fencing is not supported by Redhat. Having said that, manual fencing has no place in production. At best it is ok for PHP's salestalk POC. The short answer: Two levels of fencing is NOT possible in blades within the same enclosure. Two levels of fencing is possible in two blades housed in two different enclosures provided it does not bother other servers when you yank the power chords from the enclosure. Let me explain with another example. The solution you are trying to achieve, is possible in 2 individual physical servers in rack. One fencing level would be the management port which I would call (for the sake of this post) as "in-band" fencing device. Second would be Power fencing using power strips similar to: http://www.apc.com/products/family/index.cfm?id=70 (Disclaimer: I get zilch from any vendor for that matter so you can pick the most buttery vendor you are comfortable with) Now this I call Power fencing or "out-of-band" fencing. Now You have the the members of clluster across racks/continents (with a unbreakable redundant datalinks and power control links) and we can talk about two layer fencing. First layer or level would be the in-band fencing using IPMI/Bladecenter management port/DRAC/ILO/ALOM/RSA etc. Second would be from the power control network which would yank the power chord, as it were, off the server. So we are possibly talking about three vlans here: power control vlan, in-band vlan and data vlan. Hope it is clear now to you now. And Parvez, Yes, I do happen to know couple of HA fundas -- I have deployed and managed few RHCS clusters in the past. But then enclosure are SPOF if the member nodes are in the same enclosure anyway. phew!! Regards, Rajagopal -- Linux-cluster mailing list Linux-cluster@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-cluster
