----- Original message -----
From: Reid Wahl <nw...@redhat.com>
To: developers@clusterlabs.org
Cc: Toby Haynes <thay...@ca.ibm.com>, Gerry R Sommerville <ge...@ca.ibm.com>, Alan Y Lee <yka...@ca.ibm.com>
Subject: [EXTERNAL] Re: [ClusterLabs Developers] How to implement fencing agent with no associated hardware device with Pacemaker?
Date: Wed, Jul 29, 2020 11:42 PM
I didn't see the phrase "how to develop" until after I sent the previous message. What is the reason for needing to develop a custom fencing agent? An already-built one might save you some work.Basically, you need some reliable method to cut off an unhealthy node's access to shared storage, without depending on that node being responsive. So for example, anything that involves logging into the failed node is unreliable.On Wed, Jul 29, 2020 at 8:40 PM Reid Wahl <nw...@redhat.com> wrote:If you have a hardware **watchdog timer**, then sbd is a good option. With shared storage, you can also implement fence_sbd.KVM virtual machines also offer an emulated hardware watchdog. I'm not sure whether that would fit your criteria or not -- it depends on whether you're only excluding a management interface like an iLO/IMM, or whether you're also excluding a watchdog timer.If you can't use sbd or conventional power fencing (e.g., fence_ipmilan), then you may be able to use fence_scsi or fence_mpath since you have shared storage.What hardware or virtualization platform are you running on, and is there a particular reason you don't want to associate fencing with a hardware device?On Wed, Jul 29, 2020 at 8:34 PM Philippe M Stedman <pmste...@us.ibm.com> wrote:_______________________________________________Hi ClusterLabs developers,
I am looking into how to develop a fencing agent for Pacemaker that is not associated to any underlying hardware device. In our case we have two servers (we will expand to more in the future) which have access to shared storage. When one of the two nodes fails, we expect the surviving node to invoke our user-defined fencing agent and run a series of commands which will "expel" the lost host from accessing shared storage.
Do you have any advice on how to go about implementing such a solution? All the examples I can find online revolve around using some sort of underlying hardware device to implement fencing.
Help is greatly appreciated.
Thanks,
Phil Stedman
Db2 High Availability Development and Support
Email: pmste...@us.ibm.com
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--Regards,Reid Wahl, RHCA
Software Maintenance Engineer, Red HatCEE - Platform Support Delivery - ClusterHA
--Regards,Reid Wahl, RHCA
Software Maintenance Engineer, Red HatCEE - Platform Support Delivery - ClusterHA
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