From owner-freebsd-fs@FreeBSD.ORG Fri Feb 17 15:35:41 2012 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id A98081065673 for ; Fri, 17 Feb 2012 15:35:41 +0000 (UTC) (envelope-from freebsd-fs@m.gmane.org) Received: from plane.gmane.org (plane.gmane.org [80.91.229.3]) by mx1.freebsd.org (Postfix) with ESMTP id 5EE018FC0A for ; Fri, 17 Feb 2012 15:35:41 +0000 (UTC) Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1RyPqS-0004Jx-Ab for freebsd-fs@freebsd.org; Fri, 17 Feb 2012 16:35:36 +0100 Received: from lara.cc.fer.hr ([161.53.72.113]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 17 Feb 2012 16:35:36 +0100 Received: from ivoras by lara.cc.fer.hr with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 17 Feb 2012 16:35:36 +0100 X-Injected-Via-Gmane: http://gmane.org/ To: freebsd-fs@freebsd.org From: Ivan Voras Date: Fri, 17 Feb 2012 16:35:24 +0100 Lines: 73 Message-ID: References: <20120217141607.GA63659@freebsd.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig9E77AA4BA40123E93C37DD88" X-Complaints-To: usenet@dough.gmane.org X-Gmane-NNTP-Posting-Host: lara.cc.fer.hr User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:10.0) Gecko/20120213 Thunderbird/10.0 In-Reply-To: <20120217141607.GA63659@freebsd.org> X-Enigmail-Version: 1.3.5 Subject: Re: freebsd-swap on ssd X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 17 Feb 2012 15:35:41 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig9E77AA4BA40123E93C37DD88 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 17/02/2012 15:16, Alexander Best wrote: > hi there, >=20 > putting a freebsd-ufs partition on an ssd isn't recommended, since the = ufs > structure (unlike zfs e.g.) requires certain data to be continuously wr= itten to > a fixed location and thus will cause the ssd to quickly run out of writ= e-cycles > and die. This is outdated information as all current SSD drives will perform internal write-leveling (data relocation) in attempt to get around this. UFS also has one other benefit: it currently supports the "TRIM" operation (via BIO_DELETE) while ZFS doesn't. > but how about using a small ssd (approx. 10GB) as one entire freebsd-sw= ap > partition? will this make more sense, or are there certain structures w= ithin > the freebsd-swap partition type, which also need to be continuously wri= tten to > a fixed location? This all depends on how much swap and how often do you use it. I'd say it's a great idea if you run into out-of-memory situations rarely and then if you do run into it, you want the least performance degradation. In *all other cases* you will probably fry the SSD quickly. > another question i'd like to ask: are there also issues with read-cycle= s on > ssds? Not that I've heard of. > because i was thinking about putting a freebsd-boot partition on an ssd= > drive and only mounting it ro. this should solve the write-cycle issue = in > theory. however i'm not sure, if stuff like the dirty bit or the ufs la= bel will > also remain untouched. so even though the partition will only be mounte= d ro, > freebsd might still frequently write certain data to a fixed location o= n the > ssd drive which hosts the freebsd-boot partition.=20 It shouldn't - if the file system is mounted read-only then the underlying device will not be updated. --------------enig9E77AA4BA40123E93C37DD88 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.18 (FreeBSD) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iEYEARECAAYFAk8+c7wACgkQldnAQVacBcgAJgCg7w+pn8dAvmjg194jhb84cdeJ TzEAoNcGOmvffoWdUQMlNym11GJiIIvW =KDLy -----END PGP SIGNATURE----- --------------enig9E77AA4BA40123E93C37DD88--