Steve, just for clarity what you are actually saying is that. On Tue, 2009-09-29 at 22:45 -0400, Steve Dickson wrote: > On 09/29/2009 09:42 PM, Chris Adams wrote: > > Once upon a time, Steve Dickson <SteveD@xxxxxxxxxx> said: > >> On the server (Which is suggested): > >> * Add the following entry to the /etc/exports file: > >> / *(ro,fsid=0) Note: 'fsid=0' is explained in the exports(5) man pages. > > > > The "suggested solution" is to change your NFS servers (that work just > > fine with other clients today) to export the root filesystem to > > everybody? > > > Unfortunately the answer to your question yes... > > With version 4 there is this concept of a pseudo root. Which meanings > one can define, through exports, what the root of an export > can be. Which is a good idea because you can define /export as > the root, and nothing above /export can be accessed... But if there is a /data *(ro,fsid=0) export then that will do, but it becomes the root of the export tree against which mounts are made? > > So the idea was to use 'fsid=0' to define the V4 root of the > exports. Which, in theory is a good idea because you can define > the namespace the client have access to. A feature, I believe, > is not available in any other NFS implementation... But... > > The problem is the V4 protocol requires a pseudo root to exist. > So with Linux servers, if the fsid=0 export does not exist, the > mount will die with ENOENT (or 'No such file or directory'). > > Other NFS implementation decided not to support a definable pseudo > roots and they just made, under the covers, their '/' as the pseudo > root, along with the appropriate protections. So putting the / *(ro,fsid=0) is only adding an export of that part of the name space into the tree to make it compatible with pre-V4 name spaces. > > With F-12, I have added code to both the kernel and nfs-utils that will > do both. Allow the 'fsid=0' export to define the pseudo root and > make '/' the pseudo root (with the appropriate protections) when > there is not an fsid=0 entry. > > So Yes, one work around to make F-12 mounts work with Linux servers is > to define a pseudo root on the server with a fsid=0 export. But if > that is not an option, you can make the F12 clients only use V3 mount > (which would avoid the problem, but not take advantage of the > V4 protocol) by set either setting the '-o v3' mount option or > set the Nfsvers=3 in the new /etc/nfsmount.conf file (which would make > all mounts from that machine v3 mounts). > But the downside of the / *(ro,fsid=0) approach is we now have all of the root files (but not any other filing systems visible. So perhaps a better approach would be to specify a /V4root *(ro,fsid=0) directory being created and a bind mount for each export from the pre-V3 name space being made into that tree. Or have I missed something entirely? > I hope this helped... It did! > > steved. > > -- Howard Wilkinson <howard@xxxxxxxxxxx> Coherent Technology Limited -- fedora-devel-list mailing list fedora-devel-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/fedora-devel-list
