[ClusterLabs] Two nodes cluster issue

[Tomer Azran]

We don't have the ability to use it.
Is that the only solution?

In addition, it will not cover a scenario that the server room is down (for example - fire or earthquake), the switch will go down as well.

From: Klaus Wenninger
Sent: Monday, July 24, 15:31
Subject: Re: [ClusterLabs] Two nodes cluster issue
To: Cluster Labs - All topics related to open-source clustering welcomed, Kristián Feldsam


On 07/24/2017 02:05 PM, Kristián Feldsam wrote:
Hello, you have to use second fencing device, for ex. APC Switched PDU.

https://wiki.clusterlabs.org/wiki/Configure_Multiple_Fencing_Devices_Using_pcs

Problem here seems to be that the fencing devices available are running from
the same power-supply as the node itself. So they are kind of useless to determine
weather the partner-node has no power or simply is no reachable via network.


S pozdravem Kristián Feldsam
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On 24 Jul 2017, at 13:51, Tomer Azran <tomer.azran at edp.co.il><mailto:tomer.azran at edp.co.il> wrote:

Hello,

We built a pacemaker cluster with 2 physical servers.
We configured DRBD in Master\Slave setup, a floating IP and file system mount in Active\Passive mode.
We configured two STONITH devices (fence_ipmilan), one for each server.

We are trying to simulate a situation when the Master server crushes with no power.
We pulled both of the PSU cables and the server becomes offline (UNCLEAN).
The resources that the Master use to hold are now in Started (UNCLEAN) state.
The state is unclean since the STONITH failed (the STONITH device is located on the server (Intel RMM4 - IPMI) – which uses the same power supply).

The problem is that now, the cluster does not releasing the resources that the Master holds, and the service goes down.

Is there any way to overcome this situation?
We tried to add a qdevice but got the same results.

If you have already setup qdevice (using an additional node or so) you could use
quorum-based watchdog-fencing via SBD.


We are using pacemaker 1.1.15 on CentOS 7.3

Thanks,
Tomer.
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