*BSD News Article 64045


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From: mandtbac@news.abo.fi (Mats Andtbacka)
Newsgroups: comp.os.linux.development.system,comp.unix.bsd.freebsd.misc
Subject: Re: Ideal filesystem
Followup-To: comp.os.linux.development.system,comp.unix.bsd.freebsd.misc
Date: 11 Mar 1996 16:30:19 GMT
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G Sumner Hayes, in <glDH59i00YUvFFjspX@andrew.cmu.edu>:
>Sorry for the second post in rapid succession in reply to the same
>thread, but I thought it a good idea to break the two apart.  If you
>were to start implementing a new general purpose filesystem under a
>Unix-like OS, what considerations would be important?  What features
>would you find absolutely necessary?  What would be nice to have?  

you're trying to design (at a rough guess) twice as many different
filesystems as you'll get responses. ;-)

different people have different needs for diierent things, and in all
likelihood no one system can address them all. that said, some things
_would_ be nice to have:

 - a journalling filesystem of some kind. make it decently crashproof
 for the maximum-data-safety-while-under-artillery-shelling-with-only-
 a-lightning-rod-for-a-powersource-and-the-weather-clearing-up crowd.
 make it so that filesystems can be automagically expanded, like the
 AIX journalled(?) fs does it, because that's generally agreed to be
 c00l. try and make it fast, but that's probably not a priority.

 - a *really, really fast* filesystem for people running big news
 spools. this could be a modification of the ext2fs, using async
 metadata (who gives a hoot if news gets fried?) and fragments a la
 FFS, to minimize disk wastage. build this one to be a screamer, and
 ignore safety concerns; those who want to use it may do so at their
 own risk.

 - for the future: a filesystem that can associate POSIX.6 - style
 data with files. running POSIX.6 security, a binary needs at least
 two bitmasks, for which security properties it can have (allowed
 accesses, as it were) and which it must have (accesses it will be
 given); each of these will be in the few dozen bits range, and for
 expandability you'll want to provide for maybe three of them, of
 maybe 128 bits each (or more). that, and ACLs on this one. and make
 it fast, and provide hooks for encrypting it on the fly maybe?
 though you'd probably have to pay for a copy of POSIX.6 before you
 could earnestly start designing such a beast.
-- 
   "I'm more differed from than differing"   --  Arthur Dent