<html><head></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="font-family: monospace; ">Hi,</span><span class="Apple-style-span" style="font-family: monospace; "><br></span><span class="Apple-style-span" style="font-family: monospace; "><br></span><div><span class="Apple-style-span" style="font-family: monospace; ">I posted a less elaborate version of this question to drbd mail-list, but, unfortunately, didn't get a reply, </span></div><div><span class="Apple-style-span" style="font-family: monospace; ">maybe audience of this list has more experience.</span></div><div><span class="Apple-style-span" style="font-family: monospace; "><br></span></div><div><span class="Apple-style-span" style="font-family: monospace; ">I am trying to make xen live migration to work reliably, but wasn't successful so far.</span></div><div><span class="Apple-style-span" style="font-family: monospace; ">Here is the problem.</span></div><div><span class="Apple-style-span" style="font-family: monospace; "><br></span></div><div><span class="Apple-style-span" style="font-family: monospace; ">In a cluster configuration I have two type of resources - file systems on drbd, with explicit drbd resources configuration and </span></div><div><span class="Apple-style-span" style="font-family: monospace; ">Xen resources with implicit, using drbd-xen block device helper. For the former everything works great, but the latter doesn't work quite well.</span></div><div><span class="Apple-style-span" style="font-family: monospace; ">In order for helper script to work, drbd module has to be loaded and underlying resources up. So I have to start init.d/drbd script.</span></div><div><font class="Apple-style-span" face="monospace">I can't make it an lsb cluster resource, because stop will be disastrous for file system resources. Enable it in startup sequence breaks</font></div><div><font class="Apple-style-span" face="monospace">/usr/lib/drbd/crm-unfence-peer.sh, because cluster stack is not completely up by the time drbd script finishes, and there is no way to configure only specific resources that need to be initialized.</font></div><div><font class="Apple-style-span" face="monospace">Also, I can't find a way fence Xen resource. </font><span class="Apple-style-span" style="font-family: monospace; ">I tried fence-peer "/usr/lib/drbd/crm-fence-peer.sh -i xen_vsvn",</span></div><div><span class="Apple-style-span" style="font-family: monospace; ">where xen_svn is the name of Xen primitive, but it doesn't work, </span></div><div><font class="Apple-style-span" face="monospace">so there is a danger of starting Xen VM on an out-of-date node. Then there is no way of monitoring underlying drbd resources too. </font></div><div><font class="Apple-style-span" face="monospace">I thought of adding underlying drbd resource explicitly in the cluster, </font><span class="Apple-style-span" style="font-family: monospace; ">but I can't figure out what would be the configuration </span></div><div><span class="Apple-style-span" style="font-family: monospace; ">for "this resource can be master on both nodes, but if just on one, it's fine too".</span></div><div><font class="Apple-style-span" face="monospace">allow-two-primaries has to be allowed for live migration and at the time of migration resources are primary on both nodes, but when migration finishes, </font></div><div><font class="Apple-style-span" face="monospace">it's again primary/slave. But if I configure drbd resource in the cluster with meta master-max="2" master-node-max="1", </font></div><div><font class="Apple-style-span" face="monospace">cluster insists on having them both primary all the time.</font></div><div><font class="Apple-style-span" face="monospace"><br></font></div><div><font class="Apple-style-span" face="monospace">Hope I didn't bore you to death and there is an elegant solution for this conundrum :)</font></div><div><font class="Apple-style-span" face="monospace"><br></font></div><div><font class="Apple-style-span" face="monospace">Thank you,</font></div><div><font class="Apple-style-span" face="monospace">Vadym</font></div><div><span class="Apple-style-span" style="font-family: monospace; "><br></span></div><div><font class="Apple-style-span" face="monospace"><br></font></div></body></html>