If OTCS stuck at dbupgrade page for longer period,

Check dbupgrade.log to see if it was created. If it exists and has logs, go to the bottom of the logs and there should be an obvious error message. You can look up this error in the Knowledge Base to attempt at finding a solution to follow.

If the log is not created, check the opentext.ini file for DBUPGRADE section. If it contains lines similar to the following, this will prevent upgrade from even starting:

[DBUPGRADE]
LOGFILE=.\logs\dbupgrade.log
NEXTURL=?func=admin.clustermanagement
DOUPGRADE=TRUE
FINALRESTART=FALSE
UPGRADEINPROGRESS=true

restart servcies then navigate to func=admin.dbupgrade, this should allow you to click continue to "kick start" the upgrade process and it should show when successfully completed.