Hello NFS team ! I have sometimes trouble using NFSv4 referrals and I don't really understand where the problem come from. Here the configuration steps that expose the situation : --------------------------------------------- 1) standard nfs4 export (works) --------------------------------------------- My server export a file tree like this : /myexport/dirA /myexport/dirB To do this I have bind mounted as usual the tree root in the NFS root : mount --bind /myexport /srv/nfs4/myexport /srv/nfs4/myexport 172.16.0.0/16(sec=krb5,rw,async,no_subtree_check) (in /etc/exports) Everything is OK. ----------------------------------------------------------------- 2) dirA redirection, bind mounted to itself (works) ----------------------------------------------------------------- I now want to redirect dirA to another server "anotherserver". So I bind mount the dirA folder to itself. mount --bind /srv/nfs4/myexport/dirA /srv/nfs4/myexport/dirA /srv/nfs4/myexport/dirA 172.16.0.0/16(refer=/myexport/dirA@anotherserver,sec=krb5,rw,async,no_subtree_check) (in /etc/exports) Now the redirection works as expected. ---------------------------------------------------------------------------------- 3) mount remote dirA on the original server (first problem) ----------------------------------------------------------------------------------- But the original server need to keep access to the "dirA" files. So I need to mount the redirected "dirA@anotherserver" tree on "myserver". mount -t nfs4 -o sec=krb5 anotherserver:/myexport/dirA /myexport/dirA But as /myexport is bind mounted, this command create another mount point on /srv/nfs4/myexport/dirA. # mount ... anotherserver:/myexport/dirA on /myexport/dirA ... anotherserver:/myexport/dirA on /srv/nfs4/myexport/dirA ... So, as this command create a mount point at the right position, where the redirection start, I initially think that the initial self binded mount /srv/nfs4/myexport/dirA is useless now. So I keep the only the nfs4 mount. But strangely the redirection does not works anymore. And I don't understand where is the problem. ###### first solution tried : mount remote to /myexport/dirA, adding an additional bind mount (don't works) ###### I tried to add another bind mount over the nfs mount. I now have four mount points ! anotherserver:/myexport/dirA on /myexport/dirA ... anotherserver:/myexport/dirA on /srv/nfs4/myexport/dirA ... anotherserver:/myexport/dirA on /srv/nfs4/myexport/dirA ... anotherserver:/myexport/dirA on /myexport/dirA ... But this does not solve the problem. No redirection. ###### second solution tried : mount remote nfs directly to /srv/nfs4/myexport/dirA (works !) ###### If a mount the remote share directly to /srv/nfs4/myexport/dirA : mount -t nfs4 -o sec=krb5 anotherserver:/myexport/dirA /srv/nfs4/myexport/dirA as /myexport is bind mounted, this create another mount point on /myexport/dirA : # mount anotherserver:/myexport/dirA on /srv/nfs4/myexport/dirA ... anotherserver:/myexport/dirA on /myexport/dirA ... But the mount points are in reverse order now. And in this case it works ! I can access the remote share in /myexport/dirA. And the other clients are redirected to anotherserver. But I can't understand why... Why the mount order is so important ? Thanks ! Baptiste. -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
