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 TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by finch.gentoo.org (Postfix) with ESMTPS id 9E88E139083 for ; Sun, 10 Dec 2017 15:07:10 +0000 (UTC) Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id 1D5DBE115C; Sun, 10 Dec 2017 15:07:05 +0000 (UTC) Received: from mail-pg0-x241.google.com (mail-pg0-x241.google.com [IPv6:2607:f8b0:400e:c05::241]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by pigeon.gentoo.org (Postfix) with ESMTPS id A487AE1001 for ; Sun, 10 Dec 2017 15:07:04 +0000 (UTC) Received: by mail-pg0-x241.google.com with SMTP id f12so9239023pgo.5 for ; Sun, 10 Dec 2017 07:07:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to; bh=K4bYBIi1tfY24P/DruWId14ZBgWeJuLOo97l6BAZca8=; b=HFdoAS0Ezq/lRXQirbKOHDtLYeiZBXPxcmj9bTsDr5/haEpwXdXc0IzCkYrkP6QQNw KqQyOGm97qMM2dkIkNRosXvtp41BiTDsFDg6u0S/6rk+4qW0qQ5Df+R89m0nhHJLfoLZ venJYlzqb5U3mt3pAxbPnIErDusmiaFKt1p9XtCAJssb1xJJkPWjkUCWg3fAq2QxeEGC pkXq0jqol/dRLO/dTNb+j5Udj+DvB0QpX4PNtV+JjR5FfTuT8k5EqgeLp6umBnDh8Yvy G5GRj/s3b9ty8ihB9C6v9QMqi/ii8VU5x6xb7PJY2x3OZVlxvaVQm7C1S7rlgQPUPYzm 7oQA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to; bh=K4bYBIi1tfY24P/DruWId14ZBgWeJuLOo97l6BAZca8=; b=Fiu1WkioBTZ1+c8gV0ww7e7uGp2LqlhAkJ5y8RbFZp1PhJeMgyYdcXgo8akXyil4nI L62QrVo0FJ5No/4ELih5pH/ySHUZXHRLGM2xWjH1NtqCyHDqqIDLGTgEU8KBp3FO7k6T +5Zm5bwB8uC3GzrHvR6XAysdtZgF3VH+K/AK/JjJS50W/kAtzqCtJwdFNdEHN635cPjW FlG61FgySkaNskae7vqsKjZ0cxZb2Lgq+ODNee9oCp6CMP6ZOxYIF6l2lY6XFK1pwged v6rNx2Xhotf6vuzfAIQnNdCYB7WTHw3dQZDEQMqYRoUJICqzcfjKa0Vd8DI7mnmkydwB u48A== X-Gm-Message-State: AKGB3mIMS1PgyZcEyFBp/AmsXOQXN5VMUB9dpM2nYwyJADOIAcnCDvkc RVA1HlPeFYNN3HPRxvZ5KFByPx9y2YjFa4TWS+Cz3zyQ X-Google-Smtp-Source: AGs4zMaeLnENgsHTBb0yifA+sP3dTrIMALgIulFtdt7QVpHbdsdcbOt5zRDuaEB93e2Qz9tGE3PDeOjRGhgF7tbTniI= X-Received: by 10.98.79.152 with SMTP id f24mr4666926pfj.143.1512918422997; Sun, 10 Dec 2017 07:07:02 -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 MIME-Version: 1.0 Sender: freemanrich@gmail.com Received: by 10.100.151.169 with HTTP; Sun, 10 Dec 2017 07:07:02 -0800 (PST) In-Reply-To: <5A2D024C.2050301@youngman.org.uk> References: <20171207223545.GC18433@tp> <5A29D35D.1040901@youngman.org.uk> <1963563.zU3MYjX5FE@eve> <5A2C2B44.6060802@youngman.org.uk> <5A2D024C.2050301@youngman.org.uk> From: Rich Freeman Date: Sun, 10 Dec 2017 10:07:02 -0500 X-Google-Sender-Auth: amWMETvJE0v_DradYhA4P0wxhcw Message-ID: Subject: Re: [gentoo-user] OT: btrfs raid 5/6 To: gentoo-user@lists.gentoo.org Content-Type: text/plain; charset="UTF-8" X-Archives-Salt: 65708ed2-7d18-4655-bb83-a054293a93c4 X-Archives-Hash: 07b799a0b5af13cff41608253e4995db On Sun, Dec 10, 2017 at 4:45 AM, Wols Lists wrote: > On 09/12/17 23:36, Rich Freeman wrote: >> you instead compute 5 sets of parity so that now you have 9 sets of >> data that can tolerate the loss of any 5, then throw away the sets >> containing the original 4 sets of data and store the remaining 5 sets >> of parity data across the 5 drives. You can still tolerate the loss >> of one more set, but all 4 of the original sets of data have been >> tossed already. > > Is that how ZFS works? > I doubt it, hence why I wrote "most parity RAID systems seem to operate just as you describe." -- Rich