[CentOS] Question about clustering

Sun Jun 15 15:28:56 UTC 2014
Digimer <lists at alteeve.ca>

On 15/06/14 08:54 AM, Alessandro Baggi wrote:
> Another question is about fencing. I've ridden that a cluster must have
> fencing to be considered as such. On CentOS 6.5 there is stonith that
> concerns node level fencing. For this type of fencing I must have ilo,
> ilom, drac, and other. It's possible to have fencing without Light-out
> devices, blade power control device and other? There are other device
> that can be used for fencing? Supposing a 2 node cluster with two server
> assembled (no hp, dell, sun, ibm..) how I can implement fencing with
> stonith? I can run a cluster without fencing and what implies do not use
> fencing?

A lot of odd problems go away once fencing is working. So this is a good 
time to sort this out, then go back and see if your problems remain.

A very good way to fence machines without IPMI (etc) is to use an 
external switched PDU, like the APC AP7900 (or your country version on).


If your budget is tight, I have seen these models frequently go on sale 
for ~$200 (Canadian).

These work be allowing another node to log into the PDU and turn off the 
power going to the lost/failed node. Please do note that the brand of 
switched PDU you buy matters. For a device to work for fencing, it must 
be possible for the cluster to talk to it. This is done using a "fence 
handler", and there are many types that are supported (APC, Eaton, etc). 
So if you want to get a different make/model, please first make sure 
there is a fence handler.

Once you get this setup, see if your problems remain. If so, there is a 
good clustering mailing list at:


And if you're on freenode, #linux-cluster is also very good.


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