[Linux-cluster] Some questions - migrating from Sun to Red Hat cluster

[Ivan Fetch]

Hello,

I have been using two CentOS 5.5 virtual machines, to learn Linux clustering, as a potential replacement for Sun (Sparc) clusters. We run Red Hat Enterprise Linux, but do not yet have any production cluster experience. I've got a few questions, which I'm stuck on:

IS it possible to stop or restart one resource, instead of the entire resource group (service)? This can be handy when you want to work on a resource (Apache), without having cluster restart it out from under you, but you still want your storage and IP to stay online. It seems like the clusvcadm command only operates on services; groups of resources.

What is the most common way to create and adjust service definitions - using Lusi, editing cluster.conf by hand, using command-line tools, or something else?

For a non-global filesystem, which follows a service, is HA LVM the way to go? I have seen some recommendations against HA LVM, because LVM tagging being reset on a node, can allow that node to touch the LVM out-of-turn.

What is the recommended way to make changes to an HA LVM, or add a new HA LVM, when lvm.conf on cluster nodes are already configured to tag? I have accomplished this by temporarily editing lvm.conf on one node, removing the tag line, and then making necessary changes to the LVM - it seems like there is likely a better way to do this.

Will the use of a quarum disk, help to keep one node from fensing the other at boot (E.G> node1 is running, node2 boots and fenses node1)? This fensing does not happen every time I boot node2 - I may need to reproduce this and provide logs.

Thank you, for your help,

Ivan.