[Samba] Users Losing Data - Excel Files Not Locking Properly

[Roland Hordos]

Hi,

We have a problem like I've never seen in 8 years of running Samba in
production.  Two users can overwrite each other's open Excel
spreadsheets.  It occurs very infrequently, basically randomly, never
happens on a recently restarted smbd instance, and is extremely
difficult to troubleshoot due to samba switching process ownership from
the user to "root" shortly after opening.  I have witnessed the problem
in action just recently where, when the second user opens the
spreadsheet it doesn't prompt with it's usual "File is opened for
editing by .." message box, lsof says the file is opened by root only,
and proceeds to allow both users to edit and overwrite each others work.
Try another spreadsheet in the same area, and it works fine.  More
details on troubleshooting with LSOF in my other posting, which has not
received any responses.  Am ready to abandon Samba after many years of
faithful use -- am open to any insight on this.

Running latest production release (3.0.23c).  Running winbind in domain
mode.  Use CIFS mount points instead of NFS now to other LAN storage
areas.  I see the docs indicate that if you specify "admin users" on a
share, that all operations will be done as root, but I do not use this.
My global and a typical share setup is below.

Thank you.

Roland Hordos

_Details_

[global]
        workgroup = DOMAIN1
        realm = DOMAIN1.INT
        netbios aliases = D1PROG, D1FP, D1DATA
        server string = File Server
        security = DOMAIN
        password server = D1fp02.tundraeng.int
        log level = 1
        log file = /var/log/samba/%m.log
        max log size = 50
        socket options = TCP_NODELAY SO_RCVBUF=8192 SO_SNDBUF=8192
        printcap name = /etc/printcap
        dns proxy = No
        wins server = D1FP02
        idmap uid = 16777216-33554431
        idmap gid = 16777216-33554431
        winbind use default domain = Yes
        create mask = 0660
        directory mask = 0770
        cups options = raw

[Share1]
        path = /home/Shares/Share1
        force group = "DOMAIN1\Domain Users"
        read only = No