[Samba] Samba session timeout and oplocks

[Wim Bakker]

Hello

I have a problem that I don't know where it originates.

The following situation :
A samba server on a colocation with a public and a private
ip-address. The smb service is accessible on the private ip-address.
Clients connect to the samba server through a windows vpn
(pptp) and get an address in the same private range as the
samba server has.
They know start an application that uses a database file that's on
the samba server. Each client has it's own file.
It happens that those pptp sessions die , or the client closes
it's pptp session without closing his database file.
Now normally the smb session gets closed because the parent pptp
proces gets closed and the oplock on the database file gets removed,
but randomly , without a clear pattern , this oplock doesn't get removed
but there is some timeout , up to almost an hour, before the oplock gets
removed. This is too long because mostly the client discovers the pptp
session died , reconnects and tries to open the database file
again, which he can't because it's still locked.
My question is , what causes this timeout before the oplock is removed
and is this timeout configurable.

Thanks
Wim Bakker