<font size=2 face="sans-serif">Hi Alvise,</font><br><br><font size=2 face="sans-serif">Here is response to your question in
</font><font size=2 color=blue face="sans-serif">blue.</font><br><br><font size=2 face="sans-serif">Q - Can anybody tell me if it is normal
that all the pdisks of both my recovery groups, residing on the same physical
enclosure have free space equal to (more or less) 1/3 of the free space
of the pdisks residing on the other physical enclosure (see attached text
files for the command line output) ?</font><br><font size=2 face="sans-serif"><br></font><font size=2 color=blue face="sans-serif">Yes it is normal to see
variation in free space between pdisks. The variation should be seen in
the context of used space and not free space. GNR try to balance space
equally across enclosures (failure groups). One enclosure has one SSD (per
RG) so it has 41 disk in DA1 while the other one has 42. Enclosure with
42 disk show 360 GiB free space while one with 41 disk show 120 GiB. If
you look at used capacity and distribute it equally between two enclosures
you will notice that used capacity is almost same between two enclosure.</font><br><br><font size=2 color=blue face="sans-serif">42 * (10240 - 360) ≃ 41
* (10240 - 120)</font><br><font size=2 face="sans-serif"> </font><font size=2 color=blue face="sans-serif"><br></font><font size=2 face="sans-serif">I guess when the least free disks
are fully occupied (while the others are still partially free) write performance
will drop by a factor of two. Correct ? <br>Is there a way (considering that the system is in production) to fix (rebalance)
this free space among all pdisk of both enclosures ?</font><br><br><font size=2 color=blue face="sans-serif">You should see in context
of size of pdisk, which in your case in 10TB. The disk showing 120GB free
is 98% full while the one showing 360GB free is 96% full. This free space
is available for creating vdisks and should not be confused with free space
available in filesystem. Your pdisk are by and large equally filled so
there will be no impact on write performance because of small variation
in free space. </font><br><br><font size=2 color=blue face="sans-serif">Hope this helps</font><br><br><font size=2 color=blue face="sans-serif">Thanks,<br><br>Sandeep Naik<br>Elastic Storage server / GPFS Test <br>ETZ-B, Hinjewadi Pune India<br>(+91) 8600994314</font><br><br><br><br><font size=1 color=#5f5f5f face="sans-serif">From:
</font><font size=1 face="sans-serif">"Dorigo Alvise
(PSI)" <alvise.dorigo@psi.ch></font><br><font size=1 color=#5f5f5f face="sans-serif">To:
</font><font size=1 face="sans-serif">gpfsug main discussion
list <gpfsug-discuss@spectrumscale.org></font><br><font size=1 color=#5f5f5f face="sans-serif">Date:
</font><font size=1 face="sans-serif">31/01/2019 04:07 PM</font><br><font size=1 color=#5f5f5f face="sans-serif">Subject:
</font><font size=1 face="sans-serif">Re: [gpfsug-discuss]
Unbalanced pdisk free space</font><br><font size=1 color=#5f5f5f face="sans-serif">Sent by:
</font><font size=1 face="sans-serif">gpfsug-discuss-bounces@spectrumscale.org</font><br><hr noshade><br><br><br><font size=2 face="Tahoma">They're attached.</font><br><br><font size=2 face="Tahoma">Thanks!</font><br><br><font size=2 face="Tahoma"> Alvise</font><br><br><hr><br><font size=2 face="Tahoma"><b>From:</b> gpfsug-discuss-bounces@spectrumscale.org
[gpfsug-discuss-bounces@spectrumscale.org] on behalf of IBM Spectrum Scale
[scale@us.ibm.com]<b><br>Sent:</b> Wednesday, January 30, 2019 9:25 PM<b><br>To:</b> gpfsug main discussion list<b><br>Subject:</b> Re: [gpfsug-discuss] Unbalanced pdisk free space</font><font size=3><br></font><br><font size=2 face="sans-serif">Alvise,</font><font size=3><br></font><font size=2 face="sans-serif"><br>Could you send us the output of the following commands from both server
nodes.</font><font size=3> </font><ul><li><font size=2 face="sans-serif">mmfsadm dump nspdclient > /tmp/dump_nspdclient.<nodeName>
</font><li><font size=2 face="sans-serif">mmfsadm dump pdisk > /tmp/dump_pdisk.<nodeName></font></ul><font size=2 face="sans-serif">Regards,
The Spectrum Scale (GPFS) team<br><br>------------------------------------------------------------------------------------------------------------------<br>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 </font><a href="https://www.ibm.com/developerworks/community/forums/html/forum?id=11111111-0000-0000-0000-000000000479" target="_blank"><font size=2 color=blue face="sans-serif"><u>https://www.ibm.com/developerworks/community/forums/html/forum?id=11111111-0000-0000-0000-000000000479</u></font></a><font size=2 face="sans-serif">.
<br><br>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.
<br><br>The forum is informally monitored as time permits and should not be used
for priority messages to the Spectrum Scale (GPFS) team.</font><font size=3><br><br><br></font><font size=1 color=#5f5f5f face="sans-serif"><br>From: </font><font size=1 face="sans-serif">"Dorigo
Alvise (PSI)" <alvise.dorigo@psi.ch></font><font size=1 color=#5f5f5f face="sans-serif"><br>To: </font><font size=1 face="sans-serif">"gpfsug-discuss@spectrumscale.org"
<gpfsug-discuss@spectrumscale.org></font><font size=1 color=#5f5f5f face="sans-serif"><br>Date: </font><font size=1 face="sans-serif">01/30/2019
08:24 AM</font><font size=1 color=#5f5f5f face="sans-serif"><br>Subject: </font><font size=1 face="sans-serif">[gpfsug-discuss]
Unbalanced pdisk free space</font><font size=1 color=#5f5f5f face="sans-serif"><br>Sent by: </font><font size=1 face="sans-serif">gpfsug-discuss-bounces@spectrumscale.org</font><font size=3><br></font><hr noshade><font size=3><br><br></font><font size=2 face="Tahoma"><br>Hello,<br>I've a Lenovo Spectrum Scale system DSS-G220 (software dss-g-2.0a) composed
of<br>2x x3560 M5 IO server nodes<br>1x x3550 M5 client/support node<br>2x disk enclosures D3284<br>GPFS/GNR 4.2.3-7</font><font size=3><br></font><font size=2 face="Tahoma"><br>Can anybody tell me if it is normal that all the pdisks of both my recovery
groups, residing on the same physical enclosure have free space equal to
(more or less) 1/3 of the free space of the pdisks residing on the other
physical enclosure (see attached text files for the command line output)
?</font><font size=3><br></font><font size=2 face="Tahoma"><br>I guess when the least free disks are fully occupied (while the others
are still partially free) write performance will drop by a factor of two.
Correct ? <br>Is there a way (considering that the system is in production) to fix (rebalance)
this free space among all pdisk of both enclosures ?</font><font size=3><br></font><font size=2 face="Tahoma"><br>Should I open a PMR to IBM ?</font><font size=3><br></font><font size=2 face="Tahoma"><br>Many thanks,</font><font size=3><br></font><font size=2 face="Tahoma"><br> Alvise</font><font size=3><br></font><font size=1 face="sans-serif"><br>[attachment "rg1" deleted by Brian Herr/Poughkeepsie/IBM] [attachment
"rg2" deleted by Brian Herr/Poughkeepsie/IBM] </font><tt><font size=2>_______________________________________________<br>gpfsug-discuss mailing list<br>gpfsug-discuss at spectrumscale.org</font></tt><font size=3 color=blue><u><br></u></font><a href="http://gpfsug.org/mailman/listinfo/gpfsug-discuss" target="_blank"><tt><font size=2 color=blue><u>http://gpfsug.org/mailman/listinfo/gpfsug-discuss</u></font></tt></a><font size=3><br><br><br>[attachment "dump_nspdclient.sf-dssio-1" deleted by Sandeep Naik1/India/IBM]
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[attachment "dump_pdisk.sf-dssio-2" deleted by Sandeep Naik1/India/IBM]
</font><tt><font size=2>_______________________________________________<br>gpfsug-discuss mailing list<br>gpfsug-discuss at spectrumscale.org<br></font></tt><a href="http://gpfsug.org/mailman/listinfo/gpfsug-discuss"><tt><font size=2>http://gpfsug.org/mailman/listinfo/gpfsug-discuss</font></tt></a><tt><font size=2><br></font></tt><br><br><BR>