[Samba] The case of the disconnecting network shares

[John Gardeniers]

We recently completed our Samba 3 to Samba 4 transition without too many 
serious problems but one rather annoying issue has cropped up since the 
migration. Network shares on our file server become disconnected 
overnight, whether idle or not. This was never a problem with Samba 3 
but since upgrading Samba on the server to version 4 and joining it to 
the Samba 4 AD domain this problem is happening most, but not all, 
nights. This is merely a minor nuisance for most of our staff but is a 
serious problem for those who need to run overnight jobs over those 
shares. The inconsistency makes it even more puzzling.

We have set the auto disconnect time to -1 to disable it on all clients 
but that has made absolutely no difference. Samba itself shows nothing 
in the logs that suggests there was any sort of problem during the night 
and I have not been able to ascertain whether all clients get 
disconnected at the same time or whether it occurs at various times.

Can anyone shed any light on this and suggest possible reasons and/or 
solutions?

regards,
John