I agree with all the above, but if you really have to shrink the mdf files you'd better rebuild your indexes afterwards too. After shrinking the datafiles the indexes will get very fragmented.

@JeffTilton I think the main issue here is the network setup. You need to be able to successfully ping the IP or the fully qualified name. I also think the listener is malformed. At this stage you can try (in the listener.ora file) <br/> 1. replacing host=ggsrv1.localdomain to host=localhost 2. remove the whole SID_LIST_LISTENER block 3. rewrite the LISTENER= to : LISTENER = (DESCRIPTION_LIST = (DESCRIPTION = (ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521)) ) ) 4. start the listener using lsnrctl start listener

@JeffTilton can you also provide contents of listener.ora and sqlnet.ora?

@JeffTilton are you able to ping 192.168.1.77 ggsrv1.localdomain ggsrv1 192.168.1.78 ggsrv2.localdomain ggsrv2 both as IP and name?