[SOLVED] NFS subtree_check' or 'no_subtree_check' ?

czezz · 09-12-2012, 05:55 PM

I have shared some simple dir with NFS.
The /etc/export looks very simple:

Code:

/x 192.168.1.0/255.255.255.0(rw,sync)

I have executed NFS like this:

Code:

/sbin/rpc.portmap
/etc/rc.d/rc.nfsd start

Technically I have my share accessible from another host, however I am worried about message that appeared during /etc/rc.d/rc.nfsd start

Code:

# /etc/rc.d/rc.nfsd start
Starting NFS server daemons:
  /usr/sbin/exportfs -r
exportfs: /etc/exports [1]: Neither 'subtree_check' or 'no_subtree_check' specified for export "192.168.1.0/255.255.255.0:/x".
  Assuming default behaviour ('no_subtree_check').
  NOTE: this default has changed since nfs-utils version 1.0.x

  /usr/sbin/rpc.rquotad
  /usr/sbin/rpc.nfsd 8
  /usr/sbin/rpc.mountd

Any ideas what could it be and what to do to fix it?

jlinkels · 09-12-2012, 08:13 PM

The warning as such is harmless.

In earlier versions the default was different and you did not have to specify it. In later versions, the default behavior has been changed, and you receive a warning if you don't specify.

Check here: http://linux.die.net/man/5/exports whether you want to enable subtree checking or you want to stick to the default. In either case, specify the option explicitly and the warning disappears. Note the recommendation is to have it disabled.

jlinkels