[gpfsug-discuss] Dual server NSDs

[Alex Levin]

We are doing the similar procedure right now. Migrating from one group of
nsd servers to another.
Unfortunately,  as I understand,  if you can't afford the
cluster/filesystem downtime and not ready for 5.0 upgrade yet ( personally
I'm not comfortable with ".0" versions of software in production :) ) - the
only way to do it is remove disk/nsd from filesystem and add it back with
the new servers list.

Taking a while , a lot of i/o ...

John, in case the  single nsd filesystem, I'm afraid,  you'll have to
unmount it to change ....

--Alex



On Wed, Apr 4, 2018, 2:25 PM Buterbaugh, Kevin L <
Kevin.Buterbaugh at vanderbilt.edu> wrote:

> Hi John,
>
> Yes, you can remove one of the servers and yes, we’ve done it and yes, the
> documentation is clear and correct.  ;-)
>
> Last time I did this we were in a full cluster downtime, so unmounting
> wasn’t an issue.  We were changing our network architecture and so the IP
> addresses of all NSD servers save one were changing.  It was a bit …
> uncomfortable … for the brief period of time I had to make the one NSD
> server the one and only NSD server for ~1 PB of storage!  But it worked
> just fine…
>
> HTHAL…
>
> Kevin
>
> On Apr 4, 2018, at 4:11 AM, John Hearns <john.hearns at asml.com> wrote:
>
> I should say I already have a support ticket open for advice on this issue.
> We have a filesystem which has NSDs which have two servers defined, for
> instance:
> nsd:
>               device=/dev/sdb
>               servers=sn007,sn008
>               nsd=nsd1
>               usage=dataOnly
>
> Can I remove one of these servers?  The object is to upgrade this server
> and change its hostname, the physical server will stay in place.
> Has anyone carried out an operation similar to this?
>
> I guess the documentation here is quite clear:
>
> https://www.ibm.com/developerworks/community/wikis/home?lang=en#!/wiki/General%20Parallel%20File%20System%20(GPFS)/page/NSD%20server%20balance
> <https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.ibm.com%2Fdeveloperworks%2Fcommunity%2Fwikis%2Fhome%3Flang%3Den%23!%2Fwiki%2FGeneral%2520Parallel%2520File%2520System%2520(GPFS)%2Fpage%2FNSD%2520server%2520balance&data=02%7C01%7CKevin.Buterbaugh%40vanderbilt.edu%7Cf2ffa137afda4368e32708d59a5c513c%7Cba5a7f39e3be4ab3b45067fa80faecad%7C0%7C1%7C636584643653030858&sdata=XYE5TGimxvz54s87MPmOcK%2Fh6Fkyfmx1CpeSpF1P5DM%3D&reserved=0>
> “If you want to change configuration for a NSD which is already belongs
> to a file system, you need to unmount the file system before running
> mmchnsd command.”
> -- The information contained in this communication and any attachments is
> confidential and may be privileged, and is for the sole use of the intended
> recipient(s). Any unauthorized review, use, disclosure or distribution is
> prohibited. Unless explicitly stated otherwise in the body of this
> communication or the attachment thereto (if any), the information is
> provided on an AS-IS basis without any express or implied warranties or
> liabilities. To the extent you are relying on this information, you are
> doing so at your own risk. If you are not the intended recipient, please
> notify the sender immediately by replying to this message and destroy all
> copies of this message and any attachments. Neither the sender nor the
> company/group of companies he or she represents shall be liable for the
> proper and complete transmission of the information contained in this
> communication, or for any delay in its receipt.
> _______________________________________________
> gpfsug-discuss mailing list
> gpfsug-discuss at spectrumscale.org
>
> https://na01.safelinks.protection.outlook.com/?url=http%3A%2F%2Fgpfsug.org%2Fmailman%2Flistinfo%2Fgpfsug-discuss&data=02%7C01%7CKevin.Buterbaugh%40vanderbilt.edu%7Cf2ffa137afda4368e32708d59a5c513c%7Cba5a7f39e3be4ab3b45067fa80faecad%7C0%7C1%7C636584643653030858&sdata=Wqpqck%2FuCuzJnolVxElWG6Eky5R%2Bsc4tyvEp6we85Sw%3D&reserved=0
>
>
> _______________________________________________
> gpfsug-discuss mailing list
> gpfsug-discuss at spectrumscale.org
> http://gpfsug.org/mailman/listinfo/gpfsug-discuss
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://gpfsug.org/pipermail/gpfsug-discuss_gpfsug.org/attachments/20180404/845ef771/attachment-0002.htm>