Welcome to the forum! It appears the problem you face is TCP instability; the db connection reset in SQL Developer is just a symptom. Using the latest production release (3.2.20.09.87) will help in that manual Reconnect works much better, but the underlying problem remains.
It is impossible to guess whether you might solve the problem by changing TCP tunable parameters, as here for Oracle Solaris:
or whether you have network hardware issues. I am unsure which Oracle forum may be more appropriate than this one. Probably better to focus on the provider of your network hardware/software. Contact them or search their website.
SQL Developer Team
Edited by: Gary Graham on Mar 6, 2013 11:22 AM
Of course, network hardware includes the NIC inside your PC and any ethernet/coax/wireless router you use to connect.
If you are running the VM under VirtualBox, there is some Tuning TCP/IP stuff here:
But what about the VM guest getting partially paged out of your host's RAM on a periodic basis? Have you considered that? Does your host system have a sufficient margin of RAM above and beyond what the guest is configured to use?
Ah well, so far I have only gotten to play with VM's under VirtualBox. Oracle VM Server (either for x86 or SPARC) has its own forums, of which you may be aware already:
The solutions or workarounds in these involve SHARED vs DEDICATED server, disabling JDBC Out-of-Band-Breaks, and even a third-party product that was interfering -- nothing specific to the tool itself. I wonder if your disconnects are reproducible under SQL*Plus.
You may be in uncharted territory and probably have your work cut-out for you.
I am afraid it is not a relevant information to our case as the performance is not slow but a repeatable db disconnect around 5 minutes.
How can anyone else know what might be relevant when you won't provide information ask for that might give us a clue.
Post the details of the OS and memory and software of all of the machines involved.
Sql developer and Oracle VM versions 2 and 3 work just fine for me using OEL5, OEL6, within VirtualBox just about everything I have tried.
Repost the question in one of the VM forums.
That page only lists two of the forums (there are more) but we can't suggest which one is 'relevant' since we have no idea what hardware and software you are using.