topic Re: Permission denied on linux NFS in Operating System - Linux

Permission denied on linux NFS

Edwin Ruiz_2 — Fri, 31 Oct 2003 14:37:03 GMT

Hi!
I have one linux's file system mounted on a HP-UX server like NFS file system, but.. if i want to change into this file system i get th folowing message
oragt01 / >cd /linux
sh: /linux: Permission denied.
Why ?

Re: Permission denied on linux NFS

Jerome Henry — Fri, 31 Oct 2003 14:42:41 GMT

Hi,

Make sure your UID is the same on both ends, particularly user number on Linux box must be the same as on the other end.
Check also that NFS has been restarted after export on Linux box...

hth

J

Re: Permission denied on linux NFS

Steven E. Protter — Fri, 31 Oct 2003 15:32:43 GMT

id command for the user on both sides.

on Linux
service nfs restart

HP
/sbin/init.d/nfs.server stop
/sbin/init.d/nfs.core stop

/sbin/init.d/nfs.server start
/sbin/init.d/nfs.core start

exportfs -av

after making NFS changes on the HP side:

SEP

Re: Permission denied on linux NFS

Mark Grant — Fri, 31 Oct 2003 17:22:14 GMT

Also, just make sure the permissions actually allow you to. "ls -ld /linux". On some systems I have seen that the permissions of the mount point itself make a difference too.

Re: Permission denied on linux NFS

K.C. Chan — Fri, 31 Oct 2003 21:43:43 GMT

what is your nfs mount option, make sure you set "-o rw". what does df or bdf show?

Re: Permission denied on linux NFS

Bob_Vance — Mon, 03 Nov 2003 10:48:39 GMT

The above info on UIDs is correct, but if you are 'root' on oragt01, then there is another possible problem:

The linux directory was exported with "root_squash" (which is the default).

In this case, the remote root user id is "squashed" to the user "nobody" on the linux server. Then, the user "nobody" must have the appropriate permissions (local to the linux server) to the exported directory.

So, 2 possible fixes:

. you must export the directory in way to let remote root have access. This is accomplished with the "no_root_squash" in the /etc/exports file.

. fix the linux-local permissions on the directory for access by (local) user "nobody.

E.g.:
winky ## exportfs -v | sed 's/^/. /'
. /mnt/cdrom *(ro,async,wdelay,no_root_squash)
. /var/tmp *(rw,async,wdelay,root_squash)

notice the root_squash on "/var/tmp".

winky ## ll -d /var/tmp | sed 's/^/. /'
. dr--r--r-- 2 root root 1024 Nov 3 10:27 /var/tmp

Notice that "nobody" would not have (local) write permission on this directory.

linux1 ## mount | grep winky | sed 's/^/. /'
. winky:/var/tmp on /mnt/nfs type nfs (rw,bg,intr,soft,addr=192.168.1.7)

notice that on the remote server, the directory is imported with read-write.

But,
linux1 ## id | sed 's/^/. /'
. uid=0(root) gid=0(root) groups=0(root)
linux1 ## touch /mnt/nfs/f2 2>&1 | sed 's/^/. /'
. touch: /mnt/nfs/f2: Permission denied

this error is because "root" is squashed to "nobody".
Let's fix it

winky ## chmod 777 /var/tmp
linux1 ## touch /mnt/nfs/f2

notice no error, now :)

linux1 ## ll /mnt/nfs | sed 's/^/. /'
. total 2
. drwxrwxrwx 2 root root 1024 Nov 3 10:43 .
. drwxr-xr-x 5 root root 1024 Nov 2 09:44 ..
. -rw-r--r-- 1 65534 65534 0 Nov 3 10:27 f1
. -rw-r--r-- 1 65534 65534 0 Nov 3 10:43 f2

bv