From owner-freebsd-questions@freebsd.org Wed Sep 16 20:03:33 2020 Return-Path: Delivered-To: freebsd-questions@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 2FB783EFCF2 for ; Wed, 16 Sep 2020 20:03:33 +0000 (UTC) (envelope-from rwmaillists@googlemail.com) Received: from mail-wr1-x436.google.com (mail-wr1-x436.google.com [IPv6:2a00:1450:4864:20::436]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4Bs9yW40yQz4CqW for ; Wed, 16 Sep 2020 20:03:31 +0000 (UTC) (envelope-from rwmaillists@googlemail.com) Received: by mail-wr1-x436.google.com with SMTP id x14so8114289wrl.12 for ; Wed, 16 Sep 2020 13:03:31 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:subject:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=hg0/FrOlVV7ZDMDsMnnHFf4MklFvp7N4+pe4nTQAZTA=; b=eJ/432ah9G7unUppgTqZ7MGBTcqp1z5zCqDCQydp/fMe1yHEW+muui3J371M5yxObL fhASYYY+tAFUa/YUS4Su8/eu8aTyjO11dDTkFkRxEFd+1dDkq6lw1mtZyGbyCAFuphrL a/ahPyn9JcSrUwNIk+a/DOa3F0rl0UdeYwZXxWtLcr4lEQQWLwGxkg1eb1fmOiP5/n+h AXjYDcQ62eAOSfpC2oZH200s8lSdH5Yl416H42o/yxim0TJgShD5K/7CRjukH+8W4sAP hpeTMZGsqq+rKAH5Y/ty4dh43aj8plXO1wqC+w0nzsz1ACv1OCL85zRBQvRibKFgYfd0 BpJw== X-Gm-Message-State: AOAM532wKaezVGV2Aw0BLTUZ6PPYhhmzxXh4JRO0/mofUIUigOynrR3F LF5yaPkrRbCOWwt7X9iP+54XtnO0EN4= X-Google-Smtp-Source: ABdhPJwv92D9Z6mqCP5gmsSoxqBAz7v7RL8vjUKSmV0K+fhlBuvcN0sWJeo9/j8DPnFZDKP6cTgdOw== X-Received: by 2002:a5d:6caf:: with SMTP id a15mr28643526wra.344.1600286609294; Wed, 16 Sep 2020 13:03:29 -0700 (PDT) Received: from gumby.homeunix.com ([2.220.21.115]) by smtp.gmail.com with ESMTPSA id m23sm7218111wmi.19.2020.09.16.13.03.27 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Sep 2020 13:03:28 -0700 (PDT) Date: Wed, 16 Sep 2020 21:03:25 +0100 From: RW To: freebsd-questions@freebsd.org Subject: Re: partitioning server with 2 hard drives Message-ID: <20200916210325.08868ecc@gumby.homeunix.com> In-Reply-To: <20200916065432.508e19c3b9b5c0e44a72da3f@sohara.org> References: <20200915231901.e767350415aad298732f72cc@sohara.org> <20200916065432.508e19c3b9b5c0e44a72da3f@sohara.org> X-Mailer: Claws Mail 3.17.5 (GTK+ 2.24.32; amd64-portbld-freebsd12.1) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: 4Bs9yW40yQz4CqW X-Spamd-Bar: -- X-Spamd-Result: default: False [-2.78 / 15.00]; RCVD_VIA_SMTP_AUTH(0.00)[]; FREEMAIL_FROM(0.00)[googlemail.com]; R_SPF_ALLOW(-0.20)[+ip6:2a00:1450:4000::/36]; TO_DN_NONE(0.00)[]; RCVD_COUNT_THREE(0.00)[3]; DKIM_TRACE(0.00)[googlemail.com:+]; DMARC_POLICY_ALLOW(-0.50)[googlemail.com,quarantine]; RECEIVED_SPAMHAUS_PBL(0.00)[2.220.21.115:received]; FROM_EQ_ENVFROM(0.00)[]; MIME_TRACE(0.00)[0:+]; FREEMAIL_ENVFROM(0.00)[googlemail.com]; ASN(0.00)[asn:15169, ipnet:2a00:1450::/32, country:US]; DWL_DNSWL_NONE(0.00)[googlemail.com:dkim]; ARC_NA(0.00)[]; NEURAL_HAM_MEDIUM(-0.96)[-0.964]; R_DKIM_ALLOW(-0.20)[googlemail.com:s=20161025]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; NEURAL_HAM_LONG(-1.01)[-1.011]; MIME_GOOD(-0.10)[text/plain]; PREVIOUSLY_DELIVERED(0.00)[freebsd-questions@freebsd.org]; RCPT_COUNT_ONE(0.00)[1]; NEURAL_SPAM_SHORT(0.19)[0.194]; RCVD_IN_DNSWL_NONE(0.00)[2a00:1450:4864:20::436:from]; RCVD_TLS_ALL(0.00)[]; MAILMAN_DEST(0.00)[freebsd-questions] X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 16 Sep 2020 20:03:33 -0000 On Wed, 16 Sep 2020 06:54:32 +0100 Steve O'Hara-Smith wrote: > On Tue, 15 Sep 2020 16:10:05 -0700 > Michael Sierchio wrote: > > When, not if, a drive fails, will you find one with precisely the > > same geometry / capacity to replace the failed drive and remirror? > > Can you do > > You don't need to, you just need one big enough, and 1TB > drives are very easy to find. Just out of curiosity, does ZFS leave a small amount of space unused on a raw drive to allow for a replacement being very slightly smaller? > > so before the other drive fails (which might be statistically > > likely)? > > Unless you do something daft like RMA the drive and wait then > yes IME. In the early days of Fastmail they had a major outage where at least 3 drives failed. IIRC the other failures occurred while the RAID array was being rebuilt after the first failure. The drives were identical in every way, and I guess the the stress of a rebuild can play a part in synchronising failures.