[Samba] Randomly losing network share file communication

[Ivan Sergio Borgonovo]

On 02/16/2017 01:41 AM, Jeremy Allison via samba wrote:
> On Wed, Feb 15, 2017 at 05:23:32PM +0100, Izan Díez Sánchez via samba wrote:
>> Hi,
>>
>> Some users are experiencing problems working with files in Windows and Samba
>> shares within engineering applications. The sequence is as follows:
>> A user opens a file, e.g. a drawing, inside an application. The user works
>> fine for a while, but suddenly it cannot edit the file anymore. The only way
>> to continue working is closing and opening the file again, like if the
>> session had expired and a new one needed to be opened.

>> [2017/02/15 09:45:45.486989,  3]
>> ../source3/smbd/server_exit.c:246(exit_server_common)
>>   Server exit (NT_STATUS_CONNECTION_RESET)

> Get a wireshark trace. This usually means a TCP RST packet
> was receieved.

I've a similar problem.
The problem started when I replaced a Linux server and started to run a 
newer kernel.

As reported in a previous post (timeout after inactivity on mount.cifs 
13/02/2017) I was mount.cifs and then tar directories on a Windows 
server 2008.

Workaround was to mount the Win2008 share *just* before starting to tar.

After delaying mounting the share just before using it I still have to 
experience the problem again.

I can't blame the new server hardware. Connection with the Windows 2008 
seems solid. The script that simply does mount + tar is the same.

tar is not the culprit because mounting the share, leaving it unused for 
30+ minutes doesn't let me ls into it.

What seems to be left is the new software running on the Linux server.
I don't know how many parts are involved in mount.cifs but up to my 
understanding the most probable culprit could be some regression in the 
kernel or some small print I didn't read and this is an expected 
behaviour that I simply didn't experience before.

-- 
Ivan Sergio Borgonovo
http://www.webthatworks.it http://www.borgonovo.net