The system tab under Dashboard shows database status as unknown.
The database is busy.
Sometimes when you check on the System tab on the Dashboard, the database status will show as unknown. What this means is just that the processes querying the database were not able to get a response from the database.
The database could be just busy, so give it some time to complete what it is doing. A good example is when the database is in the middle of upgrading.
If after about half an hour the status has not changed, you can try restarting the database, using the command:
service database restart
If this does not help, contact Exinda Support.