Too much log switching is no good for database, you should see numbers not bigger than 6 per hour. Increasing the size of redo log groups is one way to lower log switch frequency, please refer to Oracle documentation on how to lower log switch frequency.
You can use the following query to determine your log [...]

You can determine users idle time using the following query:

Our Linux OAS should be started using the same NLS_LANG as client is using, in our case NLS_LANG=SLOVAK_SLOVAKIA.EE8MSWIN1250

export NLS_LANG=SLOVAK_SLOVAKIA.EE8MSWIN1250

cd $ORACLE_HOME/opmn/bin

# restart OAS
./opmnctl stopall
opmnctl: stopping opmn and all managed processes…

./opmnctl startall
opmnctl: starting opmn and all managed processes…

Assuming that there are eastern european characters used in your FMB files in labels, etc..
You need to recompile all the [...]

exp [SINGLE_QUOTE][DOUBLE_QUOTE] sys/pass@TNS as sysdba [DOUBLE_QUOTE][SINGLE_QUOTE] ..

exp '"sys/pass@TNS as sysdba"' FILE=..