Re: Buyer Beware: A Major Change in NFS (in Rawhide) is about to happen

[Steve Dickson <SteveD redhat com>]

On 10/27/2009 05:06 PM, Jason L Tibbitts III wrote:
>>>>>> "SD" == Steve Dickson <SteveD redhat com> writes:
> 
> SD> On the server (Which is suggested): Add the following entry to the
> SD> /etc/exports file:
> 
> SD> / *(ro,fsid=0)
> 
> SD> Note: 'fsid=0' is explained in the exports(5) man pages.
> 
> Could someone comment on any potential security issues that exporting
> the root in this way exposes?  
Unfortunately this entry will expose your entire root in a read-only
fashion...

> If all of my exported filesystems happen to live under /export, can I 
> export that directory instead of '/' and have things work properly?  
Only by adding the above export entry would you be able to mount /export.

But since all your exports are under /export you might want to consider 
making '/export' your pseudo root by doing something like:
   /export *(ro,fsid=0)
   /export/home *(rw)

Then the clients could do a 'mount /home' which would mount the
/export/home directory on the server... Plus if the client dose 
a mount / the only directory they could 'see' would be 'home'

> If, for whatever reason, I need to export a file system that doesn't 
> live in /export, would I still be able to mount it?
With the '/ *(ro,fsid=0)' entry, Yes, you would be able to mount other
exported directories.. 

With the '/export *(ro,fsid=0)' entry, No, the client will only see 
directories under '/export'. The rest of the filesystem would not be
seen...

I hope this helps... 

steved.