[Linux-cluster] How to fence a virtual machine in a virtual cluster?
schlegel at riege.com
Mon Aug 4 22:16:56 UTC 2008
I am running RHEL Virtual Machines as cluster services on RedHat 5.2
Dom0 nodes. The virtual machines use clustered logical volumes for
storage, /etc/xen is located on a gfs filesystem. Cluster management
using luci from a dedicated admin server. (The entire system works quite
well. Some load balancing mechanism on the Dom0 nodes would be fine, but
that is another issue...)
Now I need a second cluster, in fact I need a gfs filesystem shared
among some of the virtual machines. In general this should not be an
issue, but how can I fence a virtual machine inside of a virtual
cluster? Technically 'virsh destroy' on the Dom0 host will do the job.
a) I cannot define a script for fencing (at least using luci).
b) There is a fencing method for virtual machines in the RHEL 5.2
cluster, but it is only meant to fence virtual nodes that are part of a
mixed cluster of physical and virtual nodes.
c) Inside a virtual cluster the "Virtual Machine Fencing" is of no use,
because the virtual machine itself is a service in *another* cluster.
One would need an option to define the Dom0 host or cluster.
I somehow object to mix physical with virtual machines inside of a
cluster (and I do not want to take virtual machines part in the quorum
of the physical machines. Hypothetically the virtual machines may fence
the physical nodes, thereby shutting down the entire cluster...) . The
Dom0-cluster is intended to run VMs only and no other services. The VMs
are to provide services, and if they need cluster services, I prefer to
define aditional clusters.
Am I missing something? In fact the ability to define a script for
fencing would be sufficient from my point of view.
Or is the only real solution to join the VMs in the Dom0 cluster and
assign a dedicated failover group to them?
any hint is highly appreciated.
best regards, Gunther
Riege Software International GmbH Fon: +49 (2159) 9148 0
Mollsfeld 10 Fax: +49 (2159) 9148 11
40670 Meerbusch Web: www.riege.com
Germany E-Mail: schlegel at riege.com
Handelsregister: Managing Directors:
Amtsgericht Neuss HRB-NR 4207 Christian Riege
USt-ID-Nr.: DE120585842 Gabriele Riege
YOU CARE FOR FREIGHT, WE CARE FOR YOU
-------------- next part --------------
A non-text attachment was scrubbed...
Size: 344 bytes
Desc: not available
More information about the Linux-cluster