From mboxrd@z Thu Jan  1 00:00:00 1970
Message-ID: <af1d2f0852998cc2261f0c5c19568b69@coraid.com>
From: erik quanstrom <quanstro@coraid.com>
Date: Mon, 20 Aug 2007 14:26:15 -0400
To: 9fans@cse.psu.edu
Subject: Re: [9fans] Re: everything is a directory
In-Reply-To: <9f3897940708201036r1d877f55v38f7594f48774537@mail.gmail.com>
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> * (IIRC) Beagle daemon uses extended attributes to track files that
> were scanned and are not modified - they contain part of it's detected
> metadata, hash and DB pointer

so, to summarize.  beagle is using attributes to extend the file object.
i think the main benefit files (and a filesystem) is exactly that they
are not objects and can't be extended.

> 
> * NTFS discards the Unix concept of a file entirely - what was shown
> before as trouble with Alternate Data Streams is in fact trouble of
> keeping backward compatibility (Internally, NT doesn't have drive
> letters or any of the DOS stuff). A File in NTFS is a MFT entry with a
> bunch of attributes. Those attributes have several types/names
> defined, like DATA for file contents, one for keeping filename (for
> which there are three namespaces: DOS8.3, Windows, POSIX), one for
> legacy DOS attributes (used by the official, backward compatible API),
> one for security data, and others used mostly by system daemons
> (Although NT5+ explorer uses one to hold various comments about files.
> Rarely used by people I think).
> 
> I especially like the NTFS implementation, because it allows to use
> NTFS for most Operating Systems without modifying internal structure,
> while making it easy to add "compatibility layer"

so how does one create a sensible grep utility that operates on an arbitrary
mft entry?

> As for things that need to work with cp/mv/others, I suggest making
> better file formats or adding metadata in different file. It's not the
> smartest use of Extended Attributes/NTFS attributes :-)

i think you're missing the real difficulty with attributres.  the tools approach
works precicely because files are not objects and can't be extended.

if you want a system with extensible object storage and not a filesystem,
i think you need to think about how to add the extension to all tools at
the same time.  (or maybe you dispense with the tools approach.)  this
doesn't seem like a promising route to me.

- erik