From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from lists.gentoo.org (pigeon.gentoo.org [208.92.234.80]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id A054B15838C for ; Wed, 31 Jan 2024 21:31:14 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id EBDD92BC06B; Wed, 31 Jan 2024 21:31:08 +0000 (UTC) Received: from mail-lf1-f52.google.com (mail-lf1-f52.google.com [209.85.167.52]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id 687672BC013 for ; Wed, 31 Jan 2024 21:31:08 +0000 (UTC) Received: by mail-lf1-f52.google.com with SMTP id 2adb3069b0e04-51121637524so282594e87.1 for ; Wed, 31 Jan 2024 13:31:08 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1706736666; x=1707341466; h=content-transfer-encoding:to:subject:message-id:date:from :in-reply-to:references:mime-version:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=3zHzELftEWPEFzx0/aY857nGexRs94l3PbBn8pWB9DY=; b=TKp5CFi8yF3QcLj5sOBfAjn0MeCmLIaQIBWmQhR56DpCcH6P8n86XUWSUQjkYlHtRE xoagYVasZeETOodyYLOp922eGOPkhCSTRqbZrjfPBKX2dyQA2ONxWkRw8Eh1gKpazH8g 66pC4D0yoIuesZXM23LYyJhitA8oylyAQQrpVF+lnuHwBZW77QorNMjHqcKorDNXnygx a48JJvMhrs0l1TipEOxnRD8E5910ZVMviOXqfEnMh7QbWqnoIW60koWsOLgVXUn2vryX 4drRxlgRVqs6XJ202kopJrMsm7V2wPuzVSGnQzHa9mire3kyZy81K6CT8hi509knMo+9 eimg== X-Gm-Message-State: AOJu0YyasYjnFzbUmljBRe1JI4so6ldv7VBWG6iAZ8IXEYOwWg62H5NX pZP8vHaP2V8b93pDlsDg++Cgw2EDOn6SrsHSktFq+oeQP6mOX3xGLMuIKd4jd9vN7A/tn8zpePT sVudC2RNrbsvdkKceELYUR1bWzMEHpHi0 X-Google-Smtp-Source: AGHT+IE6+yztiOvqZ8AP/t50yyZf+6x8CcizebeK+E499nrGI89Tme3HpfPWLbLjpTFmdapy6lqEIgTb1ju+JmAraak= X-Received: by 2002:a19:2d46:0:b0:511:211b:975d with SMTP id t6-20020a192d46000000b00511211b975dmr402714lft.67.1706736665942; Wed, 31 Jan 2024 13:31:05 -0800 (PST) Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org X-Auto-Response-Suppress: DR, RN, NRN, OOF, AutoReply MIME-Version: 1.0 References: <8f5371a5-07af-456e-8517-cb9bb664fac4@youngman.org.uk> <3a14f31a-61cd-4590-baa9-e6e2a67ddc0d@youngman.org.uk> In-Reply-To: <3a14f31a-61cd-4590-baa9-e6e2a67ddc0d@youngman.org.uk> From: Rich Freeman Date: Wed, 31 Jan 2024 16:30:56 -0500 Message-ID: Subject: Re: [gentoo-user] Re: Suggestions for backup scheme? To: gentoo-user@lists.gentoo.org Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Archives-Salt: 8bea20bc-24b5-457a-b977-9d18e971cb67 X-Archives-Hash: 4cdacb59134c5c84e6c4a69a564a4fef On Wed, Jan 31, 2024 at 1:42=E2=80=AFPM Wols Lists wrote: > > On 31/01/2024 17:56, Rich Freeman wrote: > > I don't think there are > > any RAID implementations that do full write journaling to protect > > against the write hole problem, but those would obviously underperform > > zfs as well. > > This feature has been added to mdraid, iirc. > Oh, it looks like it has. Kind of annoying that it only works for a separate device. I guess you could create a separate partition on all of the devices, create a mirror across all of those, and then use that as the journal for the real raid. It would be nice if it had an option for an internal journal. I'd expect the performance of btrfs/zfs to be better of course because it just does the write to known-unused blocks, so interrupted writes don't cause any issues. Depending on how far it gets when interrupted the write will be ignored (it is just data written into unused space), or will get completed (the root of the metadata was updated and now points to a consistent new state). --=20 Rich