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

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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