db2trc fails with "Unexpected error: Trace buffer size is too small"

db2trc with any options may fail with following error sometimes (even after selecting higher buffer size): 

Solution options:

1> The first option to try is to remove all shared memory segments by recycling the db2 instance :

db2stop (force)

db2start

Optional : ipclean if required.

This will to make sure the trace shared memory segment be re-created and re-intialized.  Recycle will fix 

almost all such cases. 

2> If there was a recent upgrade then try to update the instance from install path for this instance. 

  ./db2iupdt <instance> 

3> Check if the db2trc tool is installed and available : 

    i> Check where the db2trc tool is present (default outputs included) : 

    $ which db2trc

    /home/xxxxx/sqllib/adm/db2trc

    ii> Go to that directory :

    $ cd /home/xxxxx/sqllib/adm/ 

iii> Get “ls -l” on db2trc location to check its ownership and permissions : 

$ ls -l | grep -i “db2trc"

-r-sr-s--x    1 xxxxx  build       7504075 Sep 01 19:26 db2trc

iv> Try to start trace from here : 

db2trc on

If this works, contact your OS admin to make sure the tool is accessible by including this in environment path.