Re: In Oracle Extended RAC can inaccessibility of quorum failgroup cause node eviction

From: Ls Cheng <exriscer_at_gmail.com>
Date: Sun, 16 Jun 2024 15:45:02 +0200
Message-ID: <CAJ2-Qb-sG1K82Om+YaSdGuNfXXOH61h0G8uTx1=GB82hUwdX0A_at_mail.gmail.com>



hi

the third in nfs server helps because in an extended cluster you have two storage arrays, normally people put 2 voting disk in an array and the third in second array, so if you move one of voting disk from the array which hosts 2 voting disks you won't have eviction if one arrays is turned off or under maintenance

thanks

On Sun, Jun 16, 2024 at 3:32 PM Mikhail Velikikh <mvelikikh_at_gmail.com> wrote:

> Hi,
>
> If you have three voting disks and 2 is in the same array if the
>> firmware upgrade takes more than 200 seconds then you will have eviction so
>> place the third quorum in a NFS Server and you won't have problems
>
>
> Oracle Clusterware requires that a majority of voting files should be
> available for a node to function. Losing 2 out of 3 voting files results in
> a node being restarted after 200 seconds (long disk timeout). Placing the
> third voting file on an NFS server does not really help here if it becomes
> the only voting file available out of 2 required in a configuration with 3
> voting files in total.
>
>
> https://docs.oracle.com/en/database/oracle/oracle-database/19/cwlin/storage-considerations-for-oracle-grid-infrastructure-and-oracle-rac.html#GUID-02B594C9-9D80-4E17-B4F6-30F40D9D38E4
>
>> Storage must be shared; any node that does not have access to an absolute
>> majority of voting files (more than half) is restarted.
>
>
> That is why a typical Extended Cluster configuration with 2 data sites
> requires 3 storage sites in total where the additional storage site is used
> to store the third voting file and quorum failure groups for ASM disk
> groups.
>
> https://docs.oracle.com/en/database/oracle/oracle-database/19/cwlin/about-oracle-extended-clusters.html#GUID-C12A6024-A46D-48F5-A443-E08C28AFC716
>
> Best regards,
> *Mikhail Velikikh*
>
>
>
> On Sun, 16 Jun 2024 at 12:28, Ls Cheng <exriscer_at_gmail.com> wrote:
>
>> Hi
>>
>> If you have three voting disks and 2 is in the same array if the
>> firmware upgrade takes more than 200 seconds then you will have eviction so
>> place the third quorum in a NFS Server and you won't have problems
>>
>> Thank you
>>
>>
>> On Fri, May 10, 2024 at 7:48 AM Sourav Biswas <biswas.sourav_at_hotmail.com>
>> wrote:
>>
>>> Hi All,
>>>
>>> We have scheduled storage controller firmware upgrade, which will be in
>>> rolling fashion. Storage team says, there shouldn't be any LUN availability
>>> from this array.
>>>
>>> We have multiple Extended Oracle RACs running, where the quorum disks
>>> are coming from this array.
>>>
>>> So would like to know in case of any adversities, if the quorum
>>> failgroup becomes inaccessible, do we run into a risk of node eviction.
>>>
>>> And to resolve this issue, can we manually bring down one node before
>>> storage upgrade. So that even if quorum goes offline, application can
>>> maintain all its connections.
>>>
>>> Please advise.
>>>
>>>
>>>
>>>
>>>
>>> Regards,
>>> Sourav Biswas
>>>
>>

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Received on Sun Jun 16 2024 - 15:45:02 CEST

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