<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<div class="moz-cite-prefix">drbdmanage not working if the .drbdctrl
resource is explicitly set to Primary mode is actually the
expected behavior, but the .drbdctrl resource is normally in
auto-promote mode after creation by drbdmanage.<br>
<br>
It might be the case that it had been set to Primary by accident,
e.g. by a buggy script in Proxmox 4.2 (however, I am not aware of
such a bug as of today) or by running something like 'drbdadm
primary all'.<br>
<br>
The reason for this is how drbdmanage communicates changes:<br>
<br>
The control volumes are used by drbdmanage to exchange
information. For example, when a node is added to the drbdmanage
cluster, the node entry is written to the control volumes, which
involves an auto-promotion to Primary caused by opening the
control volumes for writing. As soon as the control volumes are
closed again, an auto-demotion to Secondary takes place, a DRBD
event is sent to existing/connected drbdmanage nodes, and this
event will trigger loading of the changes on all drbdmanage nodes.
If a new node joins, then the join command will also read the
information on the control volume.<br>
<br>
Additionally, the Primary/Secondary switching is used as a means
of serialization (locking) between drbdmanage nodes. There can be
either only one writer (Primary) and no readers, or multiple
readers (Secondary) and no writers (basically an rw-lock). This is
necessary to prevent other nodes from reading incomplete/partial
updates while another node is still in the process of writing
those updates.<br>
<br>
If the .drbdctrl resource ends up being explicitly set to Primary,
it will never auto-demote after drbdmanage closes the control
volumes, but will instead stay in Primary mode, thereby locking
out all readers. As the join process on any other nodes needs to
read, and potentially even write, information from/to the control
volumes, it will hang waiting for the lock required to read the
information, and in the meantime the D-Bus connection between the
drbdmanage client and the drbdmanage server on the joining node
will time out, causing the D-Bus error to appear.<br>
<br>
For this reason, the .drbdctrl resource containing the control
volumes must not stay in Primary mode permanently on any node,
because this will prevent all other drbdmanage nodes from
receiving any new information.<br>
<br>
regards,<br>
Robert<br>
<br>
<br>
On 06/09/2016 08:43 PM, Jason Romo wrote:<br>
</div>
<blockquote
cite="mid:1B0884D7-781E-4554-B5D2-E0FCCA9EC14F@securityarsenal.com"
type="cite">
<meta http-equiv="Content-Type" content="text/html;
charset=ISO-8859-1">
Ok LinBit found a bug that was causing DRBD9 not to work. You
will find you get pending actions or DBus error when using
drbdmanage. To resolve this set:
<div class=""><br class="">
</div>
<div class="">Set Volume 0 & 1 to secondary. If set to
Primary it breaks. This could be just with the code on Proxmox
4.2.</div>
<div class="">
<div style="margin: 0px; line-height: normal; font-family:
Monaco; color: rgb(245, 245, 245); background-color: rgb(0, 0,
0);" class=""><span style="font-variant-ligatures:
no-common-ligatures" class="">drbdadm secondary .drbdctrl</span></div>
</div>
<div class=""><br class="">
</div>
<div class="">This will get you working that you can use DRBD9
with Proxmox 4.2. LinBit did a great job resolving the issue.
Sure a patch is coming.</div>
<div class="">Regards,</div>
<div class="">Jason</div>
<div class=""><br class="">
</div>
<div class=""><br class="">
</div>
<br>
<fieldset class="mimeAttachmentHeader"></fieldset>
<br>
<pre wrap="">_______________________________________________
drbd-user mailing list
<a class="moz-txt-link-abbreviated" href="mailto:drbd-user@lists.linbit.com">drbd-user@lists.linbit.com</a>
<a class="moz-txt-link-freetext" href="http://lists.linbit.com/mailman/listinfo/drbd-user">http://lists.linbit.com/mailman/listinfo/drbd-user</a>
</pre>
</blockquote>
<br>
</body>
</html>