Please ensure there is a recent VM backup/snapshot or a valid SQL backup or PGSQL backup that was taken just before the upgrade and then skip application backup.
For 9000 Upgrade:
Edit the batch file called 'Updatemanager.bat' found under C:\ManageEngine\ServiceDeskPlus-MSP\bin. Near the bottom of the batch file,after -Dtier-type=BE
add -DSDBackUp=false.
Invoke the updatemanager batch file and try for the upgrade, this should work without forcing a backup.
Make sure there is a valid backup of 8316 before doing this.
For 9200 Upgrade:
Open the UpdateManager.bat and add the below entry, AFTER the text %JAVA_OPTS%. Provide a space after this text and add the entry and provide a space.
-DSDBackUpMSP=d36cf2a688f985a
Make sure there is a valid backup of 9009 before doing this.
For 9300 upgrade:
There is an option to disable the enforced backup during upgrade by modifying the below changes in "UpdMgr.bat" file which is placed under
<ServiceDeskPlusMSP-Home>/bin/scripts/UpdMgr.bat. Please make sure you have successfully created backups of your production environment before altering the file.
Change the below content,
%JAVA_HOME%\bin\java -Xmx512m %JAVA_OPTS% -Dtier-type=BE -Dtools.discSpaceCheck=false -Duser.language="en" -Djava.library.path=.\lib\native -Dtier-id=BE1 com.adventnet.tools.update.installer.UpdateManager -u server\default\conf %*
to
%JAVA_HOME%\bin\java -Xmx512m %JAVA_OPTS% -Dtier-type=BE -DSDBackUpMSP=42F9axFrXEsxMEl -Dtools.discSpaceCheck=false -Duser.language="en" -Djava.library.path=.\lib\native -Dtier-id=BE1 com.adventnet.tools.update.installer.UpdateManager -u server\default\conf %*
Make sure there is a valid backup of 9210 before doing this.
Above will work during 9400 upgrade as well, so no need to change anything.