Date: Fri, 28 Sep 2001 15:12:04 -0700 From: Kris Kennaway <kris@obsecurity.org> To: Nate Williams <nate@yogotech.com> Cc: Kris Kennaway <kris@obsecurity.org>, Alessandro de Manzano <ale@unixmania.net>, Sean Chittenden <sean@chittenden.org>, stable@FreeBSD.ORG Subject: Re: dirpref gives massive performance boost Message-ID: <20010928151204.A16750@xor.obsecurity.org> In-Reply-To: <15284.62680.507872.259266@nomad.yogotech.com>; from nate@yogotech.com on Fri, Sep 28, 2001 at 04:08:24PM -0600 References: <20010928141246.A15515@xor.obsecurity.org> <20010928232009.A29187@libero.sunshine.ale> <20010928142611.A15946@xor.obsecurity.org> <20010928143016.H29974@rand.tgd.net> <20010928233800.B29391@libero.sunshine.ale> <20010928144146.A16221@xor.obsecurity.org> <15284.62680.507872.259266@nomad.yogotech.com>
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--82I3+IH0IqGh5yIs Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Sep 28, 2001 at 04:08:24PM -0600, Nate Williams wrote: > > > > > Well, you need to wipe the disk so that when you restore it can l= ay > > > > > things out optimally from the start. > > > >=20 > > > > But turning on soft-updates should be sufficient to get these perfo= rmance=20 > > > > boosts from this point on, correct? -sc > > >=20 > > > AFAIK SU is not related to the physical layout of data on disk, this = is > > > the work of UFS_DIRHASH. > >=20 > > No, that's something different. > >=20 > > # Directory hashing improves the speed of operations on very large > > # directories at the expense of some memory. > > # Warning: this is experimental code! > > options UFS_DIRHASH > >=20 > > The changes to dirpref are an improved on-disk layout policy for > > directories (and files?) It's enabled by default because there's no > > downside. >=20 > Again, I thought DIRHASH was an in-core data structure that helps with > cache lookups for large directories, and had no effect on the on-disk > layout. (Hence the reason why it is 'safe' to use in -stable.) Yes, like I said in the text you quoted, they *are* different things. Kris --82I3+IH0IqGh5yIs Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (FreeBSD) Comment: For info see http://www.gnupg.org iD8DBQE7tPWzWry0BWjoQKURApoZAKCADpFcjySE99eXEiQue/dDlWFD5QCgloNc 8Np3Eqe/rms9jIWgZwsRxRY= =HFag -----END PGP SIGNATURE----- --82I3+IH0IqGh5yIs-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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