Buyer Beware: A Major Change in NFS is about to happen

[Steve Dickson]

On 09/29/2009 10:10 PM, Jeremy Katz wrote:
> On Tue, Sep 29, 2009 at 8:15 PM, Steve Dickson <SteveD at redhat.com> wrote:
>>> My main concern is with installer, installing from NFS shares from older
>>> servers, say RHEL5.  How will anaconda handle mounting?  Will there be
>>> odd errors that are difficult to figure out?  Has this been tested in
>>> the anaconda environment at all?
>> This issue is this... when the the F12 does a mount to a linux server
>> and that linux server is *not* configured with a  "/ *(ro,fsid=0)"
>> export, the mount will fail with ENOENT (or No such file or directory).
>> If the server does have that export, things will work as expected...
>> So my advice is to added that one line to your rhel5 server and every
>> thing should as expected... or may even better... ;-) Another workaround
>> is to added the '-o v3' mount options... would that be hard?
> 
> Why not just see the error and fall back and try v3 programatically
> rather than forcing that upon unsuspecting users?  If someone
> explicitly specifies v4, then sure, if that fails, it should fail.
> But if they don't, we should be forgiving in what we do rather than
> giving cryptic error messages.
I looked into this... Having the kernel give a "different" kind of 
error when the "V4 beginning mount routine failed" did not look 
feasible  so figure it would be impossible to get through upstream
 
> 
>> How will anaconda handle mounting? I don't know since I believe anaconda
>> has its own mounting code so it does its own thing... and in the end
>> that will mostly likely work, since that code didn't change...
> 
> anaconda hasn't been using its own mounting code for several releases
> now.  The change to force v3 could be done, but that then makes things
> different from the real system which is something that's been trying
> to be avoided.
Well that's good to know that anaconda is using 'normal' mounts... 
And its very admirable and the right thing to do (IMHO) to do
what the "real system" will do... 

One thing about always using the '-o v3'... You will always know what
you will get.. ;-)

steved.