<font size=2 face="sans-serif">I understand you are having problems with
your cluster, but you do NOT need to have GPFS "started" to </font><br><font size=2 face="sans-serif">display and/or change configuration
paramters. You do need at least a majority of the nodes to be up
and in communcation (e.g. can talk to each other by tcp/ip)</font><br><br><tt><font size=1><b>--ccr-enable</b></font></tt><br><font size=1 face="Arial">Enables the configuration server repository
(CCR), which stores redundant copies of configuration data files on all
quorum nodes. The advantage of CCR over the traditional primary or backup
configuration server semantics is that when using CCR, all GPFS administration
commands as well as file system mounts and daemon startups work normally
as long as a majority of quorum nodes are accessible.</font><font size=2 face="sans-serif"><br></font><br><font size=2 face="sans-serif">Think about how this must work (I have
the advantage of actually NOT knowing the details, but one can reason...)</font><br><font size=2 face="sans-serif">to maintain a consistent single configuration
database, a majority of quorum nodes MUST agree on every bit of data in
the configuration database.</font><br><br><font size=2 face="sans-serif">Even to query the database and get a
correct answer, you'd have to know that a majority agree on the answer.</font><br><br><font size=2 face="sans-serif">(You could ask 1 guy, but then how would
you know if he was telling you what the majority opinion is? The minority
need not lie to mislead you, </font><br><font size=2 face="sans-serif">I don't think CCR guards against Byzantine
failures...</font><br><font size=2 face="sans-serif">The minority guy could just be out of
touch for a while...)</font><br><br><font size=2 face="sans-serif">I advise that you do some testing on
a test cluster (could be virtual)... </font><br><br><br><br><font size=1 color=#5f5f5f face="sans-serif">From:
</font><font size=1 face="sans-serif">Bryan Banister <bbanister@jumptrading.com></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)" <gpfsug-discuss@spectrumscale.org></font><br><font size=1 color=#5f5f5f face="sans-serif">Date:
</font><font size=1 face="sans-serif">07/27/2016 01:37 PM</font><br><font size=1 color=#5f5f5f face="sans-serif">Subject:
</font><font size=1 face="sans-serif">[gpfsug-discuss]
CCR troubles</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="Calibri">When I have the GPFS cluster down, some
GPFS commands no longer work like they should, or at least they did work
without CCR:</font><br><font size=2 face="Calibri"> </font><br><font size=2 face="Courier New"># mmgetstate -aL
# Which stalls for a really
stupid amount of time and then spits out:</font><br><font size=2 face="Courier New">get file failed: Not enough CCR quorum
nodes available (err 809)</font><br><font size=2 face="Courier New">gpfsClusterInit: Unexpected error from
ccr fget mmsdrfs. Return code: 158</font><br><font size=2 face="Courier New">mmgetstate: Command failed. Examine
previous error messages to determine cause.</font><br><font size=2 face="Calibri"> </font><br><font size=2 face="Calibri">And trying to change tuning parameters
now also barfs when GPFS is down:</font><br><font size=2 face="Courier New"># [root@fpia-gpfs-jcsdr01 ~]# mmlsconfig</font><br><font size=2 face="Courier New">get file failed: Not enough CCR quorum
nodes available (err 809)</font><br><font size=2 face="Courier New">gpfsClusterInit: Unexpected error from
ccr fget mmsdrfs. Return code: 158</font><br><font size=2 face="Courier New">mmlsconfig: Command failed. Examine
previous error messages to determine cause.</font><br><font size=2 face="Courier New"> </font><br><font size=2 face="Courier New"># mmchconfig worker1Threads=128,prefetchThreads=128</font><br><font size=2 face="Courier New">mmchconfig: Unable to obtain the GPFS
configuration file lock.</font><br><font size=2 face="Courier New">mmchconfig: GPFS was unable to obtain
a lock from node fpia-gpfs-jcsdr01.grid.jumptrading.com.</font><br><font size=2 face="Courier New">mmchconfig: Command failed. Examine
previous error messages to determine cause.</font><br><font size=2 face="Calibri"> </font><br><font size=2 face="Calibri">Which means I will have to start GPFS,
change the parameter, shut GPFS down again, and start GPFS up again just
to get the new setting.</font><br><font size=2 face="Calibri"> </font><br><font size=2 face="Calibri">Is this really the new mode of operation
for CCR enabled clusters?</font><br><font size=2 face="Calibri"> </font><br><font size=2 face="Calibri">I searched CCR in the Concepts, Planning,
and Install Guide and also the Adv. Admin Guide, with explanation. </font><br><font size=2 face="Calibri"> </font><br><font size=2 face="Calibri">If so, then maybe I’ll go back to non
CCR,</font><br><font size=2 face="Calibri">-Bryan</font><p><font size=3><br></font><hr><font size=1 color=#808080 face="Arial"><br>Note: This email is for the confidential use of the named addressee(s)
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