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Re: Quota: another DAV:quota-assigned-bytes question

From: Jim Luther <luther.j@apple.com>
Date: Tue, 7 Sep 2004 15:44:23 -0700
Message-Id: <76C38EA8-011F-11D9-B598-000A95DC65E0@apple.com>
To: w3c-dist-auth@w3.org

After reading all of these arguments, my input is "It's too bad the  
term "quota" was chosen in the first place."

The Mac OS X WebDAV file system does not support Unix-like file system  
quotas.

The Mac OS X WebDAV file system uses the old quota properties* to fill  
in the f_blocks (total data blocks in filesystem) and f_bfree (free  
blocks in filesystem) fields returned by statfs(2).  In the Mac OS X  
user interface, those fields become the Capacity, Available, and Used  
numbers displayed in volume information dialogs (as in "Capacity:  
100MB" "Available: 49.2 MB" "Used: 50.8 MB on disk").

On Apple's .Mac iDisk WebDAV server, if a client PUT request would  
cause a user's purchased space to be exceeded, the server returns 507  
Insufficient Storage and the WebDAV file system translates that to  
ENOSPC "No space left on device" (not to EDQUOT "Disc quota exceeded").

For our purposes, the quota properties are considered live properties  
which cannot be changed by the file system client.

So, we're using the old quota properties in a way that compatible with  
a common industry model... it just isn't the model many on this list  
are associating with the term "quota".

- Jim

* DAV: quota and DAV: quotaused as mentioned at  
<http://lists.w3.org/Archives/Public/w3c-dist-auth/2002OctDec/ 
0209.html>

On Sep 3, 2004, at 2:31 PM, Geoffrey M Clemm wrote:

>
> I'm inclined to agree with Julian.  A working group standard
> should be compatible with common industry models, unless those
> models are inherently incompatible.  So an informational RFC
> seems more appropriate unless that compatibility is achieved.
>
> Cheers,
> Geoff
>
>
> Julian wrote on 09/03/2004 12:39:25 PM:
>
>  >
>  > Brian Korver wrote:
>  >
>  > > Anyone who is going to support this use case should speak up
>  > > because if no one wants to support your proposed use case then
>  > > the issue is moot.
>  >
>  > So you're saying that the fact that the protocol as specified is
>  > incompatible with both the NTFS and Unix quota model is moot?
>  >
>  > As far as I can tell, the spec as currently published is optimized  
> for
>  > one very specific implementation. That's fine, unless people want to
>  > make it *the* quota protocol with backing of the WebDAV working  
> group.
>  >
>  > Please either simplify the protocol in a way so that other
>  > implementations become possible (moving too specific features into
>  > private extensions), or publish what you have as Informational RFC
>  > describing what one specific system is supporting today.
>  >
>  > Best regards, Julian
>  >
>  > --
>  > <green/>bytes GmbH -- http://www.greenbytes.de -- tel:+492512807760
>  >
Received on Tuesday, 7 September 2004 22:45:14 GMT

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