topic Re: NFS mount point permission denied in Operating System - Linux

NFS mount point permission denied

monu_1 — Thu, 27 Sep 2007 05:56:20 GMT

Hello All,

i have nfs server(i.e 192.168.0.2) having few portion of shared like /home/software. when a system in network (i.e. 192.168.0.4) mount that portion as a root in /mnt.
#cd /mnt
-bash: cd: /mnt: Permission denied
#ls -la /
drwx------ 2 mysql mysql 4096 Sep 22 16:31 mnt

my prob is ===> why is it showing mysql owner?

Pls suggest!

Thanks
MKS

Re: NFS mount point permission denied

Rob Leadbeater — Thu, 27 Sep 2007 06:53:09 GMT

Hi,

Maybe someone did

# chown mysql:mysql /mnt

for some reason...

Cheers,

Rob

Re: NFS mount point permission denied

Ivan Ferreira — Thu, 27 Sep 2007 06:55:56 GMT

If you umount the file system, who is the owner for /mnt? Do you have in sync the UID/GID information between the NFS server and NFS client?

Re: NFS mount point permission denied

monu_1 — Thu, 27 Sep 2007 07:10:47 GMT

Hi Ivan, Rob,
Thanks for quick reply.

Rob, when i mount it another location it also display same owner n group(mysql).

Ivan, when i umount /mnt then it display root owner n group.
Thanks,
MKS

Re: NFS mount point permission denied

monu_1 — Thu, 27 Sep 2007 07:16:07 GMT

Hi,
below is NFS sever exports entry.
# cd /proc/fs/nfs
#vi exports
# Version 1.1
# Path Client(Flags) # IPs
/home/software 192.168.0.4(rw,root_squash,sync,wdelay,no_subtree_check,uuid=166e87a6:e3cc4c24:aaa1064c:4b53622d)

Re: NFS mount point permission denied

monu_1 — Thu, 27 Sep 2007 07:19:40 GMT

Hi Ivan,

>Do you have in sync the UID/GID information between the NFS server and NFS client?

How can we sycn client n server?

Thanks,
MKS

Re: NFS mount point permission denied

Ivan Ferreira — Thu, 27 Sep 2007 07:20:38 GMT

Check the if the UID/GID information is consistent between the server and the client. If UID=500 is mysql on client, should be on server.

Re: NFS mount point permission denied

monu_1 — Thu, 27 Sep 2007 07:37:16 GMT

Hi Ivan,

I so confused why mysql is coming here? I think there is no role of mysql user.
And why mysql getting ownership after mounting that portion of server where as i m mountnig as a root on cleint?

Thanks,
MKS

Re: NFS mount point permission denied

monu_1 — Thu, 27 Sep 2007 07:41:23 GMT

Hi Ivan,

I just check that mysql id on client n sever are different.
Server:
# id mysql
uid=27(mysql) gid=27(mysql) groups=27(mysql)

Client:
# id mysql
uid=501(mysql) gid=501(mysql) groups=501(mysql)

Thanks,
MKS

Re: NFS mount point permission denied

Ivan Ferreira — Thu, 27 Sep 2007 07:46:52 GMT

Linux handles ownership by UID/GID and not username/groupname.

So in the server, the exported directory is owned by UID=501, I don't know which user is, but when you mount on the client, it looks like the owner is mysql, because uid=501 on client is mysql.

It does not matter who mounts the directory, the owner is as established in the exported directory. That is why UID/GID information must be consistent between server and client.

Remember to keep asigning points!

Re: NFS mount point permission denied

monu_1 — Thu, 27 Sep 2007 07:53:02 GMT

Hi Ivan,

Thanks a lot.

With Regards,
MKS

Re: NFS mount point permission denied

monu_1 — Fri, 28 Sep 2007 03:52:25 GMT

Hi Ivan,

If i want to shared a directory on server(/home/software) whose owner is software
(uid=501) in a network then every user on client machine in same network must have same user id to access (mount) that directory ?

Thanks & Regards,
MKS

Re: NFS mount point permission denied

Ivan Ferreira — Mon, 08 Oct 2007 17:40:43 GMT

Late answer, but yes. This is why the use of a central authentication infraestructure is indispensable. For example, the very popular LDAP or NIS+.

In this way, all clients uses the information from the central server which stores de UID/GID information, making consistent across the whole network.