[Samba] Samba 4.3. - Problem with roaming profiles

[James B. Byrne]

This problem has several elements but it did not evidence itself until
we moved from a MicroSoft AD-DC to a Samba AD-DC.

The environment is is a FreeBSD-10.3 Bhyve VM hosted on a 16 core host
also running FreeBSD-10.3.  The version of Samba is 4.3.11 obtained
through FreeBSD ports. The AD clients are all running MSWin7pro
patched up-to-date. Roaming profiles are in use.

We have an intermittent problem with one user where their Firefox
application becomes unresponsive for significant periods of time.

There appears to be a possible correlation between the incidence of
this event and the editing of a very large LibreOffice spreadsheet by
another user situated at the adjacent desk.  This spreadsheet is kept
on the desktop of the user and so forms part of that user's roaming
profile.

However, the mechanism by which any interrelationship between the two
individuals could occur escapes me.  Their equipment operates from
separate hubs and these hubs have separate direct lines back to the
central switch.

I note that in /var/log/messages the following:

 Dec 29 11:11:24 SAMBA-01 smbd[15202]: [2016/12/29 11:11:24.993469, 
0] ../source3/smbd/oplock.c:701(oplock_timeout_handler)
Dec 29 11:11:24 SAMBA-01 smbd[15202]:   Oplock break failed for file
ramnarains_hll/AppData/Roaming/Microsoft/Windows/Recent/CustomDestinations/1e9c8a0aaad0d103.customDestinations-ms
-- replying anyway


I also see these errors in /var/log/samba4/log.smbd:

[2016/12/29 11:11:24.993469,  0]
../source3/smbd/oplock.c:701(oplock_timeout_handler)
  Oplock break failed for file
ramnarains_hll/AppData/Roaming/Microsoft/Windows/Recent/CustomDestinations/1e9c8a0aaad0d103.customDestinations-ms
-- replying anyway

This is the user whose activities seem to result in the first user's
response problems.   There are no entries in the same time frames for
the user actually having thre problem.


I see a lot of these 'Oplock break failed for file' in
/var/log/samba4/log.smbd.  What does this mean and does it have any
bearing on the problems this user is experiencing?


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James B. Byrne                mailto:ByrneJB at Harte-Lyne.ca
Harte & Lyne Limited          http://www.harte-lyne.ca
9 Brockley Drive              vox: +1 905 561 1241
Hamilton, Ontario             fax: +1 905 561 0757
Canada  L8E 3C3