[gentoo-server] Samba, concurrent access from win & linux (smbmount) dbase files

[gentoo-server] Samba, concurrent access from win & linux (smbmount) dbase files

[Bastian Balthazar Bux]

Intro:
There is an ancient Clipper CA 5.4 application that run from ages on a
samba share.
The app has concurrent access to  *.DBF *.DBT *.NTX files.
Now we are (trying to) migrating -some- clients and running the app on a
"dosemu" + "Dos 5.0" environment.
Concurrent access to the same data is required from both linux and win2k.
On linux box the share is mounted with smbmount.

The problem:
Lock issued from linux are invisible to win2k and vice versa.
When some record are opened from one client it should be impossible for
another to open it too. This has always worked untill now, but the
locking is not working now if the same record is opened at the same time
from both win2k and linux+dosemu+dos5.0 .
It continue to work in multiclient linux only environment.
It continue to work in multiclient w2k only environment.
The result is a very fast corruption of index (NTX) files and possibly
the data files too (DBF, DBT) .

The supplica:
Please help a poor overcharged admin to switch at least some clients to
a nice S.O.

Readings:
http://us1.samba.org/samba/docs/man/Samba-HOWTO-Collection/locking.html
http://us1.samba.org/samba/docs/man/Samba-HOWTO-Collection/smb.conf.5.html
http://listas.cipsga.org.br/pipermail/linux-pira/2004-August/001641.html
http://www.drouillard.ca/Tips&Tricks/Samba/Oplocks.htm

Further data:
Samba has been emerged with "-*" USE flags
=========== smb.conf ===========
[global]
        security = SHARE
        passdb backend = guest
        guest account = root
        unix password sync = Yes
        max xmit = 65535
        unix extensions = No
        paranoid server security = No
        socket options = IPTOS_LOWDELAY TCP_NODELAY SO_SNDBUF=8192
        preferred master = No
        local master = No
        domain master = No
        ldap ssl = no
        hide dot files = No
        strict locking = Yes
        level2 oplocks = No
        dos filemode = Yes
        oplocks = No
        veto oplock files = /*.NTX /*.DBF /*.DBT
        blocking locks = no
        fake oplocks = no
        lock spin count = 100
        lock spin time = 18

[one]
        comment = this is one
        path = /mnt/one
        read only = No
        guest ok = Yes
=========== smb.conf ===========

====== server /etc/fstab =======
/dev/sda6 /mnt/app xfs user 0 0
====== server /etc/fstab =======

====== server kernel cfg =======

2.6.6-rc3-mm2

CONFIG_XFS_FS=y
# CONFIG_XFS_RT is not set
# CONFIG_XFS_QUOTA is not set
# CONFIG_XFS_SECURITY is not set
# CONFIG_XFS_POSIX_ACL is not set
CONFIG_SMB_FS=y
# CONFIG_SMB_NLS_DEFAULT is not set
CONFIG_CIFS=y
====== server kernel cfg =======

====== client /etc/fstab =======
//server.local/app  /mnt/gbr  smbfs 
guest,uid=1000,gid=100,ip=server.local,iocharset=utf8,codepage=cp850,ttl=10000 
0 0
====== client /etc/fstab =======

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[gentoo-server] [solved :(] Samba, concurrent access from win & linux (smbmount) dbase files

[Bastian Balthazar Bux]

Bastian Balthazar Bux wrote:
[snip]
> Concurrent access to the same data is required from both linux and win2k.
> On linux box the share is mounted with smbmount.
[snip]

Not possible at all, linux samba mount doesn't propagate locks.
The flock() and rlock() functions of clipper will never work this way.

The only solution is to share the server directory both with "nfs" and
"samba".

This open the usuals problems of locking and sync, so both the server
need to be configured in a conservative manner, nocaching, sync always etc.
The result is a much slower file server for both the environments.

I'm very open to every suggestion.

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Re: [gentoo-server] [solved :(] Samba, concurrent access from win & linux (smbmount) dbase files

[Anthony Gorecki]

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On Saturday, August 13, 2005 5:22 pm, Bastian Balthazar Bux wrote:
> I'm very open to every suggestion.

What about OpenAFS?


-- 
Anthony Gorecki
Ectro-Linux Foundation

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Re: [gentoo-server] [solved :(] Samba, concurrent access from win & linux (smbmount) dbase files

[Bastian Balthazar Bux]

Anthony Gorecki wrote:
> On Saturday, August 13, 2005 5:22 pm, Bastian Balthazar Bux wrote:
> 
>>I'm very open to every suggestion.
> 
> 
> What about OpenAFS?
> 
> 

Missed it. After some documentation reading at least three question come
in mind:

1) Are linux-2.6 kernels full supported and stable ?
   There is an afs implementation into the kernel but its limited and
   read-only.
   gentoo propose net-fs/openafs-kernel unstable on all archs.

2) How good is the throughput compared to nfs/samba in a
   single server - ten client setup ? It seem more targeted at
   scalability and reliability then to brute force transfers.
   The aplication that should run on it is based on db3 files, the file
   access (network traffic) is huge.

3) How cpu/memory intensive is it? We have a zoo of pc varing from
   pentium 3 to athlon 1.8, maximum ram installed is 384 Meg.

what's your thoughts ?

In the meantime I've installed the windows version and will make some
try this week.

Thanks
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