[DRBD-user] Dual primary// GFS2// Cannot mount /dev/drbd0 on second DRBD node

Kaloyan Kovachev kkovachev at varna.net
Tue Aug 9 14:06:54 CEST 2011

Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.

it is safe (and recommended) to cancel the manual ack, as it will execute
when xen2 needs fencing (which is not the case right now and thats why it
does not exit)

clean_start="1" have done what it was there for, so should be removed now
- you need quorum to access the gfs without risking data corruption.

<fencedevice name="human" agent="fence_manual"/> - you need a fencing
device, but use some other method (hint: take a look at fence_xvmd) instead
of manual. manual fencing is fine for tests, but not for production.

On Tue, 09 Aug 2011 13:51:00 +0200, Daniel Meszaros <spam at meszi.de> wrote:
> Hi!
> Kaloyan Kovachev:
>> Hi,
>>   manual fencing is not recommended for production clusters. You should
>> really have some fencing device.
>>   You may try to restart xen2, then it should rejoin the cluster
>> or at least 'fence_ack_manual -n xen2' will be safe to answer
>> 'absolutely'
>> as that is what you did - manually fenced the node :)
> Ok, I did the following...
> - On "xen1": fence_ack_manual -n xen2
> - Rebooted "xen2"
> - Started DRBD on "xen2" as secondary
> - Made "xen2" primary after the resync was finished
> - Restarted cman
> - Mounted /dev/drbd0 successfully
> - Created a test file on each node, edited it and watched the change on 
> the other node.
> It appears to work fine now.
> But (please excuse this collection of silly questions) the command for 
> manual fencing is still "open" on "xen1". How can I return to automatic 
> fencing? I am afraid canceling (Ctrl+c) the command on "xen1" could do 
> something nasty.
> BTW, I suppose that the cluster.conf (a copy is below the email text)  
> is set up wrong - which could have caused the problem. My concerns are:
> - clean_start="1" ... which I configured to get the thing running on 
> "xen1" when there was still no cluster configured on "xen2"
> - <fencedevice name="human" agent="fence_manual"/> ... which I took over

> from the mentioned DRBD/GFS2 manual page
> What do you think?
> CU,
> Daniel.
> # cat /etc/cluster/cluster.conf
> <?xml version="1.0"?>
> <cluster name="cluster" config_version="1">
> <!-- post_join_delay: number of seconds the daemon will wait before
>                          fencing any victims after a node joins the
>         post_fail_delay: number of seconds the daemon will wait before
>                          fencing any victims after a domain member fails
>         clean_start    : prevent any startup fencing the daemon might
>                          It indicates that the daemon should assume all 
> nodes
>                          are in a clean state to start. -->
> <fence_daemon clean_start="1" post_fail_delay="0" post_join_delay="3"/>
> <clusternodes>
> <clusternode name="xen1" votes="1" nodeid="1">
> <fence>
> <!-- Handle fencing manually -->
> <method name="human">
> <device name="human" nodename="xen1"/>
> </method>
> </fence>
> </clusternode>
> <clusternode name="xen2" votes="1" nodeid="2">
> <fence>
> <!-- Handle fencing manually -->
> <method name="human">
> <device name="human" nodename="xen2"/>
> </method>
> </fence>
> </clusternode>
> </clusternodes>
> <!-- cman two nodes specification -->
> <cman expected_votes="1" two_node="1"/>
> <fencedevices>
> <!-- Define manual fencing -->
> <fencedevice name="human" agent="fence_manual"/>
> </fencedevices>
> _______________________________________________
> drbd-user mailing list
> drbd-user at lists.linbit.com
> http://lists.linbit.com/mailman/listinfo/drbd-user

More information about the drbd-user mailing list