[gpfsug-discuss] Question regarding quorum nodes

[Wally Dietrich]

Hi, Tina. I hope the issues have been resolved.

You said that "I have a number of nodes which now have stale file handles." In my experience, that happens pretty often when an NSD node goes down, even if another NSD node serves the needed data and metadata. I was almost always able to fix the stale file handle problem by running the mmmount command again on the clients that were getting the stale file system handles errors. I might have had to run mmumount first, but probably not.

Regarding adding a quorum node, I'm not sure it will have much benefit because you will still have a single point of failure (because you only have one working NSD node). If you can get the failed NSD node back up quickly, you might not need to add another quorum node. 

Wally

email: wallyd at protonmail.com


------- Original Message -------
On Thursday, September 7th, 2023 at 9:39 AM, gpfsug-discuss-request at gpfsug.org <gpfsug-discuss-request at gpfsug.org> wrote:


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> 1. Question regarding quorum nodes (Tina Friedrich)
> 2. Re: Question regarding quorum nodes (Danny Lang)
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> ----------------------------------------------------------------------
> 
> Message: 1
> Date: Thu, 7 Sep 2023 14:28:55 +0100
> From: Tina Friedrich tina.friedrich at it.ox.ac.uk
> 
> To: "gpfsug-discuss at gpfsug.org" gpfsug-discuss at gpfsug.org
> 
> Cc: theteam at arc.ox.ac.uk
> 
> Subject: [gpfsug-discuss] Question regarding quorum nodes
> Message-ID: f0949731-e02b-99f1-a693-d67e2773fac4 at it.ox.ac.uk
> 
> Content-Type: text/plain; charset="UTF-8"; format=flowed
> 
> Hello All,
> 
> I hope someone can answer this quickly!
> 
> We have - it seems - just lost one of our NSDs.The other took over as it
> should - but unfortunately, the protocol nodes (i.e. I have a number of
> nodes which now have stale file handles. (The file system is accessible
> on the remaining NSD server and a number of other clients.)
> 
> Unfortunately, in the 'home' cluster - the one that ones the disks - I
> only have, five servers; three of which are quorum nodes, and of course
> the failed NSD server is one of them.
> 
> The question is - can I add quorum nodes with one node down, and can I
> remove quorum functionality from a failed node?
> 
> Tina
> 
> 
> 
> ------------------------------
> 
> Message: 2
> Date: Thu, 7 Sep 2023 13:39:00 +0000
> From: Danny Lang danny.lang at crick.ac.uk
> 
> To: "gpfsug-discuss at gpfsug.org" gpfsug-discuss at gpfsug.org
> 
> Cc: "theteam at arc.ox.ac.uk" theteam at arc.ox.ac.uk
> 
> Subject: Re: [gpfsug-discuss] Question regarding quorum nodes
> Message-ID:
> DB9PR05MB8715AC665CCA2E428F5DCBF9C0EEA at DB9PR05MB8715.eurprd05.prod.outlook.com
> 
> 
> Content-Type: text/plain; charset="utf-8"
> 
> Hi Tina,
> 
> The command you're looking for is:
> 
> 
> mmchnode
> 
> https://www.ibm.com/docs/en/storage-scale/4.2.0?topic=commands-mmchnode-command
> 
> This will allow you to add quorum nodes and to remove.
> 
> ------
> 
> I would advise checking everything prior to running commands. ?
> 
> Thanks
> Danny
> 
> ________________________________
> From: gpfsug-discuss gpfsug-discuss-bounces at gpfsug.org on behalf of Tina Friedrich tina.friedrich at it.ox.ac.uk
> 
> Sent: 07 September 2023 2:28 PM
> To: gpfsug-discuss at gpfsug.org gpfsug-discuss at gpfsug.org
> 
> Cc: theteam at arc.ox.ac.uk theteam at arc.ox.ac.uk
> 
> Subject: [gpfsug-discuss] Question regarding quorum nodes
> 
> 
> External Sender: Use caution.
> 
> 
> Hello All,
> 
> I hope someone can answer this quickly!
> 
> We have - it seems - just lost one of our NSDs.The other took over as it
> should - but unfortunately, the protocol nodes (i.e. I have a number of
> nodes which now have stale file handles. (The file system is accessible
> on the remaining NSD server and a number of other clients.)
> 
> Unfortunately, in the 'home' cluster - the one that ones the disks - I
> only have, five servers; three of which are quorum nodes, and of course
> the failed NSD server is one of them.
> 
> The question is - can I add quorum nodes with one node down, and can I
> remove quorum functionality from a failed node?
> 
> Tina
> 
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