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jberryman
Asked: 2010-01-02 14:37:39 +0800 CST

Files mounted over NFSv4 are owned by 4294967294, UIDs and GIDs match

  • 772

I have two identical linux machines (identical images launched in amazon EC2) and I am trying to mount an exported directory over NFSv4. Here is what the mounted directory looks like on the client machine:

root@server:~# ls -l /websites/
drwxr-xr-x  6 4294967294 4294967294   92 2010-01-01 20:21 logs
drwxr-xr-x  2 4294967294 4294967294   20 2009-12-23 01:14 monit.d
...

I double checked to make sure that the UIDs were matching

Here is the mount command I run from the client

/sbin/mount.nfs4 $MASTER_DN:/ /websites -o rw,_netdev,async

And here is the /etc/exports entry on the server machine:

/websites 10.0.0.0/8(fsid=0,no_subtree_check,rw,no_root_squash)
linux

5 Answers

  1. read here http://blather.michaelwlucas.com/archives/796

    If the NFSv4 client and server domain names doesn’t match,all the usernames will show up as “nobody.”

    1. edit /etc/idmapd.conf and set Domain on server and client to the "localdomain"

      [General]

      Domain = localdomain

      [Translation]

      Method = nsswitch

    2. change the /etc/default/nfs-common file (on both your server and client): set NEED_IDMAPD= yes

    3. start idmapd service

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  2. As explained in UID /GID with NFS and ZFS, NFSv4 doesn't use UIDs. I was having a similar problem and was able to work around it by using NFSv3. This just entails adding -o vers=3 to the mount command. Of course, if you do need to use NFSv4 this response won't be of much use to you.

    • 8

  3. This is a user id mapping problem. For some reason the system is using the "nobody" account instead of the true account ids. Check your squashing options and your idmapd.conf file.

    Here is a thread I found that discusses the problem, this links to the post of interest, http://www.mail-archive.com/[email protected]/msg03303.html.

    FYI, 4294967294 is -2, if treated as a 32-bit signed integer. -1 or -2 are used on various Linux distros for the nobody UID and nogroup GID (in the passwd file the highest 16 bit unsigned number, 65535, is generally used).

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  4. You need to change the /etc/default/nfs-common file (on both your server and client): set NEED_IDMAPD to yes.

    At least this helped for me.

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  5. We are using the NFS options anonuid and anongid to set the user/group IDs the server will use for files created by anonymous. If these are not set, "nobody" and "nogroup" will be used - which may vary depending on OS version and distribution. So a 

    /websites 10.0.0.0/8 
    (fsid=0,no_subtree_check,rw,no_root_squash,anonuid=1001,anongid=1001)
                                              ^^^^^^^^^^^^^^^^^^^^^^^^^^

    may to the trick (with 1001 being a valid and usable UID/GID on your server).

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