[lug] NSLU2

[Ron Wright]

On 2/11/06, Bear Giles <bgiles at coyotesong.com> wrote:
> Perhaps someone can clarify something for me.  I thought that Samba and
> NFS can't coexist.  I mean, obviously, you can run both servers at the
> same time.  But you can't export the same files with both Samba and
> NFS.   (Or mod_dav, god forbid.)
>
> I remember the old days when you weren't even supposed to run local apps
> against exported filesystems, but that shouldn't be a problem with
> kernel-based servers.
>
> The problem is caching and locking.  Kernel based servers will use the
> kernel's on pages so they shouldn't be a problem.  But can the
> userspace(?) samba server do the same?  Or does it have internal caching
> that can get out of step with the rest of the system?  (E.g., I know
> that mmap and advisory locks can go a long way.)

>From the smb.conf man page

       kernel oplocks (G)

              For UNIXes that support kernel  based  oplocks  (currently  only
              IRIX and the Linux 2.4 kernel), this parameter allows the use of
              them to be turned on or off.

              Kernel oplocks support allows Samba oplocks  to be broken  when-
              ever  a local UNIX process or NFS operation accesses a file that
              smbd(8) has oplocked.  This  allows  complete  data  consistency
              between  SMB/CIFS, NFS and local file access (and is a very cool
              feature :-).

              This parameter defaults to on, but is translated to a  no-op  on
              systems  that  no  not  have  the  necessary kernel support. You
              should never need to touch this parameter.

              Default: kernel oplocks = yes

I would assume that it should now read "2.4+ kernels".

Ron