In some sites locking problems surface as soon as a server is installed; in other sites
locking problems may not surface for a long time. Almost without exception, when a locking
problem does surface, it will cause embarrassment and potential data corruption.
Over the past few years there have been a number of complaints on the Samba mailing lists
that have claimed that Samba caused data corruption. Three causes have been identified
Incorrect configuration of oplocks (incompatible with the application
being used). This is a common problem even where MS Windows NT4 or MS Windows
200x-based servers were in use. It is imperative that the software application vendors'
instructions for configuration of file locking should be followed. If in doubt,
disable oplocks on both the server and the client. Disabling of all forms of file
caching on the MS Windows client may be necessary also.
Defective network cards, cables, or hubs/switches. This is generally a more
prevalent factor with low-cost networking hardware, although occasionally there
have also been problems with incompatibilities in more up-market hardware.
There have been some random reports of Samba log files being written over data
files. This has been reported by very few sites (about five in the past 3 years)
and all attempts to reproduce the problem have failed. The Samba Team has been
unable to catch this happening and thus unable to isolate any particular
cause. Considering the millions of systems that use Samba, for the sites that have
been affected by this as well as for the Samba Team, this is a frustrating and
vexing challenge. If you see this type of thing happening, please create a bug
report on Samba
Bugzilla without delay.
Make sure that you give as much information as you possibly can to help isolate the
cause and to allow replication of the problem (an essential step in problem isolation and correction).