From owner-freebsd-questions@freebsd.org Thu Oct 22 13:15:18 2015 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 29EE9A1A38B for ; Thu, 22 Oct 2015 13:15:18 +0000 (UTC) (envelope-from jcigar@ulb.ac.be) Received: from relaygateway02.edpnet.net (relaygateway02.edpnet.net [212.71.1.211]) (using TLSv1 with cipher RC4-SHA (128/128 bits)) (Client CN "*.edpnet.net", Issuer "Go Daddy Secure Certificate Authority - G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 7D0C71EE5 for ; Thu, 22 Oct 2015 13:15:16 +0000 (UTC) (envelope-from jcigar@ulb.ac.be) X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AvwHAD3gKFZNbXNd/2dsb2JhbABegzZULULAARcKhTJKAoFITQEBAQEBAYELhC8BAQQBAQEgKwgYCxALGAkTDgICDwUNBgEJCCQIBwQBHASHegMWCbFzjhkNR4QgAQEBBwEBAQEWCYZ3hH6CUIFrAQFQB4JpgUUFliuFGYUcdIFtCIFYh2OLHoNdg3BjhAU8NAeEfIFAAQEB X-IPAS-Result: AvwHAD3gKFZNbXNd/2dsb2JhbABegzZULULAARcKhTJKAoFITQEBAQEBAYELhC8BAQQBAQEgKwgYCxALGAkTDgICDwUNBgEJCCQIBwQBHASHegMWCbFzjhkNR4QgAQEBBwEBAQEWCYZ3hH6CUIFrAQFQB4JpgUUFliuFGYUcdIFtCIFYh2OLHoNdg3BjhAU8NAeEfIFAAQEB X-IronPort-AV: E=Sophos;i="5.20,182,1444687200"; d="asc'?scan'208";a="344781282" Received: from 77.109.115.0.93.adsl.dyn.edpnet.net (HELO mordor.lan) ([77.109.115.93]) by relaygateway02.edpnet.net with ESMTP/TLS/DHE-RSA-AES256-SHA; 22 Oct 2015 15:15:11 +0200 Date: Thu, 22 Oct 2015 15:15:10 +0200 From: Julien Cigar To: "Brandon J. Wandersee" Cc: Adam Vande More , FreeBSD Questions , krad Subject: Re: gjournal and TRIM: A safe combination? Message-ID: <20151022131510.GY87605@mordor.lan> References: <867fmh12nq.fsf@WorkBox.Home> <86pp081glq.fsf@WorkBox.Home> <20151021143525.GX87605@mordor.lan> <86lhaw107r.fsf@WorkBox.Home> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="BzSjWsyRXn5FzoOl" Content-Disposition: inline In-Reply-To: <86lhaw107r.fsf@WorkBox.Home> User-Agent: Mutt/1.5.24 (2015-08-30) X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 22 Oct 2015 13:15:18 -0000 --BzSjWsyRXn5FzoOl Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Oct 21, 2015 at 02:38:16PM -0500, Brandon J. Wandersee wrote: >=20 > Julien Cigar writes: > > Correct me if I'm wrong but, unless there is a bug in Soft Updates (SU), > > your FS will, in theory, never be corrupted with SU only. >=20 > If I read this right, then, would gjournal be overkill for typical > desktop/laptop use? UFS2 is perhaps the only filesystems I've ever > encountered in common use that doesn't have data journaling enabled by > default, so that's thrown me off somewhat... It depends of your needs, but for a typicaly desktop use it seems a bit overkill to me. Contrary to other filesystems UFS doesn't need journaling to avoid=20 _corruption_ as SU is an alternate approach to maintain metadata integrity. One important thing to remember is that neither SU, or SU+J, or any journaled metadata prevents data loss: corruption !=3D data loss. This is where gjournal (and data=3Djournal on EXT-like FS) comes in as datas and metadatas are written in the journal _before_, so you avoid corruption and data loss. I hope SU+J will be fixed one day ... >=20 > --=20 > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > :: Brandon Wandersee :: > :: brandon.wandersee@gmail.com :: > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > 'A common mistake that people make when trying to design something > completely foolproof is to underestimate the ingenuity of complete > fools.' > - Douglas Adams > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D > _______________________________________________ > freebsd-questions@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.o= rg" --=20 Julien Cigar Belgian Biodiversity Platform (http://www.biodiversity.be) PGP fingerprint: EEF9 F697 4B68 D275 7B11 6A25 B2BB 3710 A204 23C0 No trees were killed in the creation of this message. 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