I have scanned our 19 Tb database, and found several issues that needs to be addressed before the conversion can run.
Having disconnected the DMU client, I now would like to connect again and proceed, but it "hangs" and the "Connecting to the database" window.
The database session first ran this sql (sql_id=gavt6k1c3jnf7) for more than 20 minutes, where the wait was "control file sequential read":
SELECT COUNT ( * )
FROM SYSTEM.dum$tables dt,
WHERE (dt.convertible + dt.too_large + dt.over_limit + dt.invalid) > 0
AND dt.obj# = t.obj#
AND t.ts# = f.ts#
AND f.file# = v.file#
AND v.file# = fe.fenum
AND BITAND (fe.festa, 18) = 0
That sql is now finished, but now the session hangs (waits) on the same "control file sequential read" waits, without a sql ( at lease not one visible in Grid Control ).
I have tried shutting down the database and connect again, but the issue re-occurs consistently.
Alert log does not show anything other then sporadic logswitches, no (known) O/S issues etc.