[Samba] Writing to shares directly

[Rubin Bennett]

On Fri, 2008-10-03 at 11:31 -0500, fixed wrote:
> Thank you for your reply.
> 
> We are using Samba to create a redundant file system for failover between
> two servers. I am wondering if this is even a recommended use for Samba.
> 
> For example:
> 
> app01
> ------
> /data/shares/app01 (local)
> /data/shares/app02 (remote)
> 
> app02
> -----
> /data/shares/app01 (remote)
> /data/shares/app02 (local)
> 
> So we have written our apps to write to both shares - if one goes down,
> this isn't a bad thing as it will read from the local share.
> 
I don't see any issue with this although there are perhaps better tools
for writing to 2 systems simultaneously such as DRBD.

Anyhoo, as I said before the issue that you'll need to be watchful of is
ensuring that the filesystem permissions remain compatible with how you
access the files via the samba shares.

A dirty hack may be to mount the local filesystem as a samba share and
not access it directly via the filesystem ever.

Rubin

> Thank you
> 
> Ogden
> 
> On Fri, 3 Oct 2008, Rubin Bennett wrote:
> 
> > On Fri, 2008-10-03 at 09:46 -0500, Ogden wrote:
> > > Within a Samba configuration, is it not advisable to create files on the
> > > directory on the local machines themselves? Out setup is like so:
> > >
> > > Server 1 (where the files reside):
> > >
> > > /data/shares/app01
> > >
> > > Server 2 (mounts the above drive):
> > > /data/mounts/app01
> > >
> > >
> > > If, on Server 1, I create a file:
> > >
> > > # echo test > /data/shares/app01/test
> > >
> > > The file is created, but on Server 2, I cannot seem to edit the file as I
> > > get the permission denied warning.
> > >
> > > However, if I mount the /data/shares/app01 directory on Server 1 and write
> > > to that directory, I can write to the files from other machines fine.
> > >
> > It's not necessarily bad practice, but you have to use care when using
> > multiple access methods to the Samba shared directory because Unix
> > filesystem permissions trump Samba perms.
> >
> > Example:if you create a file as root (like you did above), then you have
> > to make sure it's writable as the samba user who accesses the share.
> >
> > I.e. if /data/shares/app01/test is 755 and owned by root:root then only
> > members of the root group would be able to write to that file.
> >
> > If you're creating files as root that you expect to write to as another
> > user, you should expect to adjust ownership and/ or permissions on the
> > files you create.
> >
> > Rubin
> >
> > > Within smbstatus, it says the file is  RDONLY    and oplock is NONE when
> > > I write to the directory itself and not the mount.
> > >
> > > I'm wondering if I set things up alright and whether it is bad practice to
> > > write to the directory directly?
> > >
> > > Thank you
> > >
> > > Ogden
> > >
> >
-- 
Rubin Bennett
RB Technologies
http://thatitguy.com
rbennett at thatitguy.com
(802)223-4448

Think for yourselves and let others enjoy the privilege to do so, too.
~Voltaire