I am running CentOS 7 and need to mount an NFS share which is protected by credentials. I have read the nfs, mount, mount.nfs manuals and can't find the right options that work! I think the right options are 'user' and 'pass', but I've tried 'username' and 'password' and everything inbetween, but I get:

mount -t nfs -o user=root,pass=mypass lserver:/root /mnt/d0
mount.nfs: an incorrect mount option was specified

Can someone tell me the right syntax/options to make this work? (It really shouldn't be this hard)


Specifying username and password are options for cifs (samba), but not nfs. According to this CentOS Documentation:

NFS controls who can mount an exported file system based on the host making the mount request, not the user that actually uses the file system. Hosts must be given explicit rights to mount the exported file system. Access control is not possible for users, other than through file and directory permissions.

  • I missed that! But why is 'user' a valid parameter for NFS mounts? – TSG Feb 1 '17 at 23:44
  • 1
    Where do you see that? There is no user option in man mount.nfs. – Timothy Martin Feb 1 '17 at 23:51
  • When I try adding parameters, they all give invalid option errors, but the 'user' option does NOT generate an invalid option error – TSG Feb 2 '17 at 1:06
  • See @Adonis' answer for why user= exists – Ryan V. Bissell Apr 20 '18 at 21:58

The user option is related to allow any users on your system allowed to mount the file system. See the "non-superuser mounts" of man mount


sudo mount -t nfs -O user=root,pass=mypass lserver:/root /mnt/d0

Notice that the 'O' is a capital letter.


This works under CentOS

mount.cifs // /mnt/myshare -o user=myuser

(it asks for the password - you can add it on the commandline probably via pass=)

Run this by itself to see all the options:


Usage: mount.cifs -o

Mount the remote target, specified as a UNC name, to a local directory.

Options: user= pass= dom=

Less commonly used options: credentials=,guest,perm,noperm,setuids,nosetuids,rw,ro, sep=,iocharset=,suid,nosuid,exec,noexec,serverino, mapchars,nomapchars,nolock,servernetbiosname= directio,nounix,cifsacl,sec=,sign,fsc

Options not needed for servers supporting CIFS Unix extensions (e.g. unneeded for mounts to most Samba versions): uid=,gid=,dir_mode=,file_mode=,sfu

Rarely used options: port=,rsize=,wsize=,unc=,ip=, dev,nodev,nouser_xattr,netbiosname=,hard,soft,intr, nointr,ignorecase,noposixpaths,noacl,prefixpath=,nobrl

Options are described in more detail in the manual page man 8 mount.cifs

To display the version number of the mount helper: mount.cifs -V

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