Re: Apache Alias and QNTC directory

[Scott Klement <midrange-l@xxxxxxxxxxxxxxxx>]

Hi Greg,

When NFS submits the directory listing over the network, it passed the 
user id and group id numbers (UID & GID, respectively) along with the 
filenames.  When the operating system checks authorities to access these 
objects, it does so according to these UID/GID numbers.

For example, suppose you have a SYSTEM-A with profile SKLEMENT as UID 1, 
and SYSTEM-B has GWILBURN as UID 1.

Now suppose SYSTEM-A creates an NFS mount of SYSTEM-B's data. When the 
people on SYSTEM-A look at a directory listing, it transmits the files 
with the uid/gid.  Since a file owned by GWILBURN on system B has uid 1, 
it will appear as owned by SKLEMENT (since he is uid 1 on SYSTEM-A)

When authorities are checked, likewise, SYSTEM-A will believe SKLEMENT 
to have ownership of the object rather than GWILBURN because it is 
checked by the number, not the name.

Therefore, the recommendation is that you keep the UID/GID in sync 
across all systems that use NFS.


*Scott Klement*
Scott Klement Consulting LLC
https://www.scottklement.com
Cell: (414) 731-6581

IBM Champion

On 5/5/23 12:45 PM, Greg Wilburn wrote:
> I know what a UID is... I just don't know how it plays a role in this configuration.
>
> -----Original Message-----
> From: MIDRANGE-L<midrange-l-bounces@xxxxxxxxxxxxxxxxxx>  On Behalf Of Rob Berendt
> Sent: Friday, May 5, 2023 12:42 PM
> To: Midrange Systems Technical Discussion<midrange-l@xxxxxxxxxxxxxxxxxx>
> Subject: Re: Apache Alias and QNTC directory
>
> UID, not user id.  It's WAAAYYY down on DSPUSRPRF.
> User ID number . . . . . . . . . . . . . . :   3598
> Group ID number  . . . . . . . . . . . . . :   *NONE
>
> On Fri, May 5, 2023 at 11:04 AM Greg Wilburn <
> gwilburn@xxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> > THANK YOU to all!
> >
> > Patrik, I didn't feel like anyone provided a "terse" response 😊 (I'm a
> > very "direct" person).
> >
> > With Richard's link, the link from IBM (and everyone that responded), I
> > was able to get NFS fired up and working.
> > Richard - I would add to your github document if I could have captured
> > better screen shots on the Windows 2019 server - but we remote into it, so
> > the resolution is not the best.
> > https://www.ibm.com/support/pages/using-nfs-mount-remote-file-systems
> >
> > *I used the MOUNT command and OPTIONS exactly as Richard outlined, except
> > I used the server name instead of the IP.
> >
> > Jim, I'm confused about the UID/GID statement below... I was under the
> > impression that NFS doesn't use "user id" to authenticate?
> >
> > Also, if we go this route... do I need to do anything special during an
> > IPL or system save (i.e. unmount file systems)?  I know I'll have to place
> > the MOUNT command in my startup (IPL).
> > Anything else to consider?
> >
> > Thanks again Everyone!
> > Greg
> >
> > -----Original Message-----
> > From: MIDRANGE-L<midrange-l-bounces@xxxxxxxxxxxxxxxxxx>  On Behalf Of Jim
> > Oberholtzer
> > Sent: Thursday, May 4, 2023 6:57 PM
> > To: Midrange Systems Technical Discussion<midrange-l@xxxxxxxxxxxxxxxxxx>
> > Subject: Re: Apache Alias and QNTC directory
> >
> > In this case I believe IBM i followed the UNIX methods etc, so they should
> > be the same, or very similar, so Patrik, your experience should be valid.
> >
> > We’ve used NFS extensively at customers and it works really well, but, big
> > but, UNIX uses the UID/GID not the IBM user profile so those need to match
> > up between the systems.   The UID and GID can be found with DSPUSRPRF, and
> > scroll down to near bottom. I ‘think’ windows also uses the UID.
> >
> > Jim Oberholtzer
> > Agile Technology Architects
> >
> >
> >
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