I have two DBs (8.1.5) on a Win 2K server.

Because the Veritas backup has no Oracle Agent, I execute a simple SQL file at 11pm that connects as sysdba and issues a shutdown immediate. (For both DBs) This works fine.

At 2am I use another simple SQL script to restart them.

Both DBs begin to open but hang at the MOUNT stage with:

ORA-01102: cannot mount database in EXCLUSIVE mode
ORA-09341: scumnt: unable to mount database
OSD-04400: unable to acquire internal semaphore for process

Now I've tracked a bug (855721) that describes this functionality (!) perfectly. It advocated restarting the services as the only way to start an instance that has previously failed at the MOUNT stage before.

Okay - its a bug, but how can I trace what is causing the DBs to fail to MOUNT in the first place?

Until very recently the SQL file just stopped and started 1 DB. This worked without problem. I added a startup and shutdown for a 2nd DB and this problem has begun to occur - if intermittently.

The scripts are very simple:

CONNECT sys/pwd as sysdba@db1
shutdown immediate
CONNECT sys/pwd as sysdba@db2
shutdown immediate

and the same for startup. Could the nature of the scripts be causing the DBs to hang at MOUNT stage?