75 ways to demystify DB2 #51: Techtip: How to change disk tiebreakers in Purescale setup

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Run steps as instance owner :

db2cluster -cfs -list -tiebreaker
db2cluster -cm -list -tiebreaker

Make sure the CFS and CM level tibreakers are type disk.

Stop all the applications and deactive the databases.

db2stop
db2stop instance on <member-host>  [repeat for all member hosts]
db2stop instance on <cf-host>      [repeat for all CF hosts]

Run steps as cluster service admin (root) :

db2cluster -cm -enter -maintenance -all
db2cluster -cfs -enter -maintenance -all

db2cluster -cfs -set -tiebreaker -majority
db2cluster -cfs -set -tiebreaker -disk  <exact-disk-path, example  /dev/hdisk5>

db2cluster -cm -exit -maintenance
db2cluster -cfs -exit -maintenance -all

db2cluster -cm -set -tiebreaker -majority
db2cluster -cm -set -tiebreaker -disk <exact-disk-path,   example /dev/hdisk4>

Run as db2 instance owner:

db2start instance on <cf-host>     [repeat for all CF hosts]
db2start instance on <member-host> [repeat for all member hosts]
db2start

Then,  check the tibreakers to verify,
db2cluster -cfs -list -tiebreaker
db2cluster -cm -list -tiebreaker