nfs issue, can't read certain files

[Masaki Birchmier]

I am exporting an NFS directory read-only.
On the system that mounts, I can't read files where the owner user id is not resolved. In other words, that user doesn't exist on the system that mounts. The files have world read permissions.

Any ideas?
Thanks, Masaki

[Craig Rants]

A good NFS Troubleshooting Doc.

GL,
C

http://docs.hp.com/hpux/onlinedocs/B1031-90048/00/00/42-con.html

[Shannon Petry]

If exporting read only and ID's do not exist, a failure to read files is NOT from directory/file permissions but NFS permissions.

Set anon=0 or any other valid UID on each system to fix the problem. If exporting read only, setting anon to 0 is not a security risk.

Regards,
Shannon

[Joaquin Gil de Vergara]

due to security reasons nfs deny any root access to anything exported...

if you create a file by root in a exported nfs volume owner will be id -1

other users must exist in both machines (same ID)

[Shannon Petry]

Actually the anon uid is set by passwd user=nobody and can be changed to whatever you want.
Default on solaris is UID: -65534, HP-UX:-1.
Since it is erroneous to mount a read only file system as root, what occurs is that NFS can map the ID so permission is granted under world permissions. Unless this is an automount there will be no problems. If it's an automount then the mount occurs a bit differently and problems can occur.

I'd still recommend you make a generic user on each machine and map annon to that though, as root exports of any size, shape and color can have unknown side effects.

Regards,
Shannon

[Masaki Birchmier]

Thanks for your input,
It turns out I was missing user "nobody" from my export server. I added it, set "use uid of user 'noboday'", but no go. Also tried specifying UID to other like "0", still o go.

to pick up the changes, I ran exportfs -av, restarted nfs.server, nfs.client but no joy.

Masaki

[Shannon Petry]

Any time you make changes to a NFS server, you need to only run "exportfs -a" to apply the changes.

NOTE: This does not effect clients who have already mounted the server.
TO update clients you must "umount" the NFS directory, then remount the directory. Now the new mount options will apply to both.

Regards,
Shannon