[OpenAFS] a question about CellServDB and DNS alias

Giovanni Bracco giovanni.bracco@enea.it
Thu, 24 Mar 2022 10:09:58 +0100


So on Unix/linux systems only the ip address is relevant.

Is that true both for OpenAFS client and servers?

On Windows  clients there must be consistency between the ip address and 
the DNS entry of the #hostname portion of CellServDB file

Giovanni

On 23/03/22 21:57, Mark Vitale wrote:
> Giovanni,
> 
>> On 23 Mar 2022, at 11:15 AM, Giovanni Bracco <giovanni.bracco@enea.it> wrote:
>>
>> In the documentation for the CellServDB file (both client & server)
>> https://docs.openafs.org/Reference/5/CellServDB.html
>>
>> it is declared that is the "fully qualified hostname"
>> that must be provided in the line defining a dbserver.
>>
>> So even if a dbserver has an alias in the DNS different from the hostname, it is definitely the hostname that must be provided in the CellServDB line.
>>
>> Have I well understood?
>>
>> So reading the CellServDB file OpenAFS considers that at a given IP address it will find the hostname defined in the CellServDB file line.
>>
>> (by the way: we do not have AFSDB records in our DNS)
> 
> The "#hostname" portion of a CellServDB server line is only processed
> by OpenAFS when running on Windows.  It is ignored on other platforms.
> 
> I only know that whatever is there has to be resolvable by Windows
> gethostbyname().  I don't know if it has to be fully-qualified, but
> I suspect that depends on the configuration of your Windows resolver.
> 
> If it cannot be resolved for any reason, the Windows code falls back
> to the IP address specified in the first token.
> 
> (src/WINNT/afsd/cm_config.c)
> 
> Regards,
> --
> Mark Vitale
> Sine Nomine
> 
> 

-- 
Giovanni Bracco
phone  +39 351 8804788
E-mail  giovanni.bracco@enea.it
WWW http://www.afs.enea.it/bracco