Date: Fri, 28 Sep 2001 16:08:24 -0600 From: Nate Williams <nate@yogotech.com> To: Kris Kennaway <kris@obsecurity.org> Cc: Alessandro de Manzano <ale@unixmania.net>, Sean Chittenden <sean@chittenden.org>, stable@FreeBSD.ORG Subject: Re: dirpref gives massive performance boost Message-ID: <15284.62680.507872.259266@nomad.yogotech.com> In-Reply-To: <20010928144146.A16221@xor.obsecurity.org> 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>
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> > > > Well, you need to wipe the disk so that when you restore it can lay > > > > things out optimally from the start. > > > > > > But turning on soft-updates should be sufficient to get these performance > > > boosts from this point on, correct? -sc > > > > AFAIK SU is not related to the physical layout of data on disk, this is > > the work of UFS_DIRHASH. > > No, that's something different. > > # 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 > > 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. 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.) Nate To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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