[gpfsug-discuss] Spectrum Scale Replication across failuregroups

[IBM Spectrum Scale]

I think it would be wise to first set the failure group on the existing 
NSDs to a valid value and not use -1.  I would also suggest you not use 
consecutive numbers like 1 and 2 but something with some distance between 
them, for example 10 and 20, or 100 and 200.

Regards, The Spectrum Scale (GPFS) team

------------------------------------------------------------------------------------------------------------------
If you feel that your question can benefit other users of  Spectrum Scale 
(GPFS), then please post it to the public IBM developerWroks Forum at 
https://www.ibm.com/developerworks/community/forums/html/forum?id=11111111-0000-0000-0000-000000000479
. 

If your query concerns a potential software error in Spectrum Scale (GPFS) 
and you have an IBM software maintenance contract please contact 
1-800-237-5511 in the United States or your local IBM Service Center in 
other countries. 

The forum is informally monitored as time permits and should not be used 
for priority messages to the Spectrum Scale (GPFS) team.



From:   Stephen Ulmer <ulmer at ulmer.org>
To:     gpfsug main discussion list <gpfsug-discuss at spectrumscale.org>
Cc:     "gpfsug-discuss-request at spectrumscale.org" 
<gpfsug-discuss-request at spectrumscale.org>
Date:   04/16/2019 09:18 AM
Subject:        Re: [gpfsug-discuss] Spectrum Scale Replication across 
failure groups
Sent by:        gpfsug-discuss-bounces at spectrumscale.org



I believe that -1 is "special", in that all -1’s are different form each 
other. So you will wind up with data on several -1 NSDs, instead of a -1 
and a 2.

In fact you probably didn’t specify -1, it was likely assigned 
automatically.

Read the first paragraph in the failureGroup entry in:

https://www.ibm.com/support/knowledgecenter/en/STXKQY_5.0.2/com.ibm.spectrum.scale.v5r02.doc/bl1adm_mmcrnsd.htm

I do realize that the subsequent paragraphs do confuse the issue somewhat, 
but the first paragraph describes what’s happening.

Liberty,

-- 
Stephen



On Apr 16, 2019, at 8:38 AM, Prasad Surampudi <
prasad.surampudi at theatsgroup.com> wrote:

We have a filesystem with 'system' and 'v7kdata' pools. All the NSDs in 
v7kdata are with failure group '-1'. Filesystem metadata is already 
replicated. Now we are planning to replicate the filesystem data. So, If I 
add new NSDs with failure group '2'  in the v7kdata pool,  would I be able 
to replicate GPFS data between NSDs with '-1' failure group and NSDs with 
failure group '2' ? i.e have one copy of file on NSD with '-1' and another 
copy on NSD with failure group '2' ? or Do I have to change the NSDs with 
failure group '-1' to '1' ?
 

mobile 302.419.5833|fax 484.320.4306|psurampudi at theATSgroup.com
Galileo Performance Explorer Blog Offers Deep Insights for Server/Storage 
Systems



_______________________________________________
gpfsug-discuss mailing list
gpfsug-discuss at spectrumscale.org
http://gpfsug.org/mailman/listinfo/gpfsug-discuss
_______________________________________________
gpfsug-discuss mailing list
gpfsug-discuss at spectrumscale.org
https://urldefense.proofpoint.com/v2/url?u=http-3A__gpfsug.org_mailman_listinfo_gpfsug-2Ddiscuss&d=DwICAg&c=jf_iaSHvJObTbx-siA1ZOg&r=IbxtjdkPAM2Sbon4Lbbi4w&m=qj8cjidW9IKqym8U4WV2Buxy_hsl7bpmELnPNc8MYPg&s=hNTiNvPnIYhBCgPOm2NLtq9vP1MIVCipuIA8snw7Eg4&e=





-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://gpfsug.org/pipermail/gpfsug-discuss_gpfsug.org/attachments/20190416/f880046a/attachment-0002.htm>