From owner-freebsd-geom@FreeBSD.ORG  Tue Nov 23 12:44:54 2004
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To: RW <list-freebsd-2004@morbius.sent.com>
From: "Poul-Henning Kamp" <phk@phk.freebsd.dk>
In-Reply-To: Your message of "Tue, 23 Nov 2004 12:39:33 GMT."
             <200411231239.33577.list-freebsd-2004@morbius.sent.com> 
Date: Tue, 23 Nov 2004 13:44:51 +0100
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cc: freebsd-geom@freebsd.org
Subject: Re: gbde: ufs & ffs 
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In message <200411231239.33577.list-freebsd-2004@morbius.sent.com>, RW writes:
>
>Why does the gbde section of the Handbook recommend running fsck -p -t ffs, 
>which calls  fsck_ffs, when ordinary filesystems are checked with fsck_ufs.

ufs and ffs are two sides of the same one filesystem.  The difference
is mainly that ufs _could_ potentially be shared with another filesystem
using a different storage policy as well.

Therefore, in my opinion, the correct name is FFS.

>According to 
><http://sixshooter.v6.thrupoint.net/jeroen/faq.html#UFS-DIFF-FFS>, ffs runs 
>on top of ufs "providing directory structure information, and a variety of 
>disk access optimizations".

That is 180 degrees wrong.

>Am I correct in thinking that soft-updates 
>protect ffs from inconsistency, so that only a background ufs check is 
>required?

yes.

>Is it possible to background check gbde partitions? If so, can it be done 
>after booting is complete?

yes.
-- 
Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG         | TCP/IP since RFC 956
FreeBSD committer       | BSD since 4.3-tahoe    
Never attribute to malice what can adequately be explained by incompetence.