[OpenAFS] -dynroot - what does it really do?

[jarausch@igpm.rwth-aachen.de]

On 27 Feb, Derek Atkins wrote:
> jarausch@igpm.rwth-aachen.de writes:
> 
>> Derek Atkins write:
>> 
>> > The -dynroot option causes /afs to be built as a "DYNamic ROOT".
>> > It only contacts servers when you explicitly access /afs/<cell>
>> 
>> I experience problems with this last sentence.
>> 
>> Case I
>>   If I use -dynroot my client machine comes up even if the server is not
>>   running.
> 
> This is absolutely correct.  This is _supposed_ to happen.  As I said,
> when using synroot it will only attempt to contact the server when you
> explictly access /afs/<cell>.  Note that when you use -dynroot it
> _NEVER_ loads the "root.afs" volume from the server -- it jumps
> directly to the "root.cell" volume when you access /afs/<cell>.
> 
>> Case II
>>   If I don't use -dynroot my client machine hangs with
>>   "Lost contact to server ..."
>>   until the server becomes available.
> 
> This is also absolutely correct.  Without -dynroot the client tries to
> load "root.afs" volume, and in your case it cannot do so...  So it
> times out.
> 
>> In both cases, if the server becomes available,
>> doing an ls -l /afs doesn't show the afs tree. Doing
>> fs examine /afs/home
>> reports that there is no /afs/home file.
> 
> Right.. /afs is built dynamically as you access AFS cells.  Think about
> it like an automounter -- it will auto-mount a cell when you access it,
> but not before.
> 
> So, is your cell actually named "home"?  I highly doubt it.  Do you have
> an alias set up (note that aliases in "root.afs" don't count here.

I probably misunderstood quite a lot. If have "mounted" my afs-volumes
directly into root.afs and I cannot see these as you have described.
Probably I should "mount" my volumes under /afs/<CELL>/ since any files
below /afs/<CELL> are indeed visible.
Is there any chance to make my root.afs visible without restarting AFS
or even reboot my client?
>
> What happens if you "cd /afs/my.cell.name/" ???
Yes, it works just fine, see my misunderstandings above.

> Is the server actually running when you're trying these tests?
> Do you try running "fs checks" after the server comes up, just to be
> sure?
> 
>> On the other hand, if the server is running
>> while the client machine boots the behaviour
>> is normal. This is all with openafs-1.2.8 on
>> Linux
> 
> Well, sure.  But that's nothing new. ;)

Many thanks for your hints and explications.
Is there a document where one can find such details?

Cheers,
Helmut.

-- 
Helmut Jarausch

Lehrstuhl fuer Numerische Mathematik
Aachen University
D 52056 Aachen, Germany