Skip site navigation (1)Skip section navigation (2)
Date:      Sat, 7 Feb 2004 15:37:08 +0100
From:      Harald Schmalzbauer <h@schmalzbauer.de>
To:        Erik Trulsson <ertr1013@student.uu.se>, Stijn Hoop <stijn@win.tue.nl>
Cc:        freebsd-current@freebsd.org
Subject:   Re: Reserved space (WAS: How to calculate bsdlabel size)
Message-ID:  <200402071537.16757@harrymail>
In-Reply-To: <20040207141103.GA65140@falcon.midgard.homeip.net>
References:  <20040206072244.GT908@cirb503493.alcatel.com.au> <20040207131735.GA2803@pcwin002.win.tue.nl> <20040207141103.GA65140@falcon.midgard.homeip.net>

next in thread | previous in thread | raw e-mail | index | archive | help

--Boundary-02=_cgPJA3bWjJHcuYi
Content-Type: text/plain;
  charset="iso-8859-15"
Content-Transfer-Encoding: quoted-printable
Content-Description: signed data
Content-Disposition: inline

On Saturday 07 February 2004 15:11, Erik Trulsson wrote:
> On Sat, Feb 07, 2004 at 02:17:35PM +0100, Stijn Hoop wrote:
> > On Fri, Feb 06, 2004 at 01:57:11PM -0500, Garrett Wollman wrote:
> > > <<On Fri, 6 Feb 2004 09:44:58 +0100 (CET),=20
=3D?iso-8859-1?q?Claus=3D20Guttesen?=3D <cguttesen@yahoo.dk> said:
> > > > Does the algorithm(s) rely only on percentage of free
> > > > space? On a five TB (netto) filesystem eigth percent
> > > > is approx. 410 GB which seems quite alot.
> > >
> > > A good Data Structures text will prove to you that the efficiency of
> > > hashing algorithms of the sort that the UFS block allocator uses
> > > depends only on the occupancy ratio and not on the absolute number of
> > > free hash slots.
> >
> > Which translates into what wrt this question? That the 8% of free space
> > is really necessary for the UFS block allocator to function efficiently?
>
> Yes, that is exactly what it translates to.

Hm, I don't really understand why, but anyway, what performance degradation=
 do=20
I have to expect when lowering it to 2%?

=2DHarry

--Boundary-02=_cgPJA3bWjJHcuYi
Content-Type: application/pgp-signature
Content-Description: signature

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.3 (FreeBSD)

iD8DBQBAJPgcBylq0S4AzzwRAruLAJ9KCHHucTwkysriaXEhN0FVttEcwACePUMU
AfyhWvQoGxDUtTausLlWgbM=
=NJlZ
-----END PGP SIGNATURE-----

--Boundary-02=_cgPJA3bWjJHcuYi--



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200402071537.16757>