[OpenAFS] What filesystem?

Christopher D. Clausen cclausen@acm.org
Tue, 7 Mar 2006 15:55:30 -0600

Jeffrey Hutzelman <jhutz@cmu.edu> wrote:
> On Monday, March 06, 2006 09:17:23 AM -0600 "Christopher D. Clausen"
> <cclausen@acm.org> wrote:
>>> It's kind of hard to explain, but Windows people and Unix people
>>> think differently about what they are serving out.  AFS grew up in
>>> a world where Unix admins wanted to distribute executable
>>> "applications" as well as data from a single name space tree.  In
>>> the enterprise, Unix workstations actually run their applications
>>> off of the network.
>> Warning: I am a Windows person.
>> I'm not at an enterprise.  I'm at a University.
> So am I.  A University _is_ an enterprise, and a challenging one at
> that, because of the highly heterogeneous community.  At Carnegie
> Mellon, we use an enterprise-grade distributed filesystem (AFS), and
> we use it in exactly the way Jeff described.  Here's why:

UIUC's shared storage (if you can call it that) is 100MB of WebDAV space 
per student: http://www.cites.uiuc.edu/netfiles/  As such, we don't use 
an enterprise-grade filesystem :-(

Since this is essentially useless for home directories, almost every 
department runs their own fileserver, possibly independent of the 
central Active Directory domain, though usually not.  Since there is 
only a single a Windows or Mac OS fileserver, it makes sense to have 
machines and the server joined to campus Active Directory to push the 
password services to the central IT organization.

We don't just have a heterogeneous community, we have a heterogeneous IT 

In such a model, it makes sense for pre-existing Windows file servers to 
be hooked in to a central directory structure like AD and use a shared 
tree for storage like MS Dfs.  It is also very easy to purchase and 
setup a single additional Windows server as a replica of the first one 
for high-availability and a backup at some level.

That is all I am suggesting.

> Back in the 1980's (long before I got to CMU), a few people had a
> grand vision.  They imagined a world in which every student and staff
> member had his or her own small computer.  All of these machines
> would be similar hardware and run the same software, maintained and
> distributed by a central support group, which would also manage the
> machines so that individual users wouldn't have to know how.

I think this is where UIUC differs.  The problem is that there isn't a 
single entity managing all computers (as is the case at most schools.) 
There is a centrally maintained Active Directory domain, with seperate 
OUs delegated to various other autonomous groups: 

Christopher D. Clausen