From owner-freebsd-stable@freebsd.org Thu Aug 16 23:33:08 2018 Return-Path: Delivered-To: freebsd-stable@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 010E5107A148 for ; Thu, 16 Aug 2018 23:33:08 +0000 (UTC) (envelope-from fjwcash@gmail.com) Received: from mail-lf1-x12d.google.com (mail-lf1-x12d.google.com [IPv6:2a00:1450:4864:20::12d]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 6D5EC7E346 for ; Thu, 16 Aug 2018 23:33:07 +0000 (UTC) (envelope-from fjwcash@gmail.com) Received: by mail-lf1-x12d.google.com with SMTP id o72-v6so2472658lfk.1 for ; Thu, 16 Aug 2018 16:33:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=4C4/tM6XRLBKLG7Q9zrfvHQ8suaJlYbkU9pTXU6KsjQ=; b=foMPGIUUuVFYI7Q5xSsD1NMcZggUqnlypJH4ubDMppzF072zE6Ts8ZOaiLt288eHks p+MqvReJ1PIveBJoTeM6UXo9IdQN8mIErKzqRLMRL7xB4nAet7aB0X9iw0wRfmh69PWX xfjg6DnTIulG8qVJ8t60Q5HwDqhWkLwwnpRIY+cTtpoS3vMXyu2vK+xQC4L6GQWPLIFR F4Xjo2HqjzxTE9RCSVC4uJp9DhRMXPJNfepLcJYt2KxxHa5e/RVfOGjd9dkZ+WVVKJm+ gD1WwVBssfuMuL6WrE69/0vyqMXt2BR6bVx+WjKga9Ev2ypp7AVkwVT8jyrUH4kKlPS/ vylQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=4C4/tM6XRLBKLG7Q9zrfvHQ8suaJlYbkU9pTXU6KsjQ=; b=TIi/SA5BDNuXQVNt+z6PeYZ2qMkSIdVqowlYMKj/Z5MVy0YqVYBr++PAjd6+wqPtNx TPAXa/kyICLQ6VnQwz6nLZFbbNTGUEI7L+h+0mm2jmF1KvP4vXp7D+pyvRfyrqFtmtz1 3OZmtvsjf5/5NdJG7Gp/Il9FvbfXpseIvQQKGocHvxHwaE0TvtspIM0MKT3gOw9+TI6b oAr9KsPUj31KMcaMF4XorlPehqt1tV+qzOIgrXl1CjaApT7fxeeWe2pQ9sUyB5RdFgi+ jUOSy3m9OLzjzmeStGZGerR3yxaDF+g1POomFQ2uo3oz02NVlQ+f2xUP3X1DuDHMlE1n tzDQ== X-Gm-Message-State: AOUpUlH+JtzTa9tQcmM+U2DO9xVNZvRGFWZAWKRRUy6ekkEwah6J1I0Q z5XK5lPvfUCmZwu/iANvFoWDz0zdPXRGKoOlK/QJHA== X-Google-Smtp-Source: AA+uWPz6A3Vqf+IrPljy+uD6/mtAy6rRSLED/BQuh9Y8EgGGTPLtQmFGLoKqdAoIb252oGqOZ/77vvTX5ign6F6Pnik= X-Received: by 2002:a19:9646:: with SMTP id y67-v6mr20194534lfd.130.1534462386021; Thu, 16 Aug 2018 16:33:06 -0700 (PDT) MIME-Version: 1.0 References: <469d704c-3635-2da9-39b6-1f25eae384d7@multiplay.co.uk> In-Reply-To: <469d704c-3635-2da9-39b6-1f25eae384d7@multiplay.co.uk> From: Freddie Cash Date: Thu, 16 Aug 2018 16:32:52 -0700 Message-ID: Subject: Re: zfs boot size To: Steven Hartland Cc: FreeBSD Stable Content-Type: text/plain; charset="UTF-8" X-Content-Filtered-By: Mailman/MimeDel 2.1.27 X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 16 Aug 2018 23:33:08 -0000 On Thu, Aug 16, 2018, 4:22 PM Steven Hartland, wrote: > The recommended size for a boot partition has been 512K for a while. > > We always put swap directly after it so if a resize is needed its easy > without and resilvering . > > If your pool is made up of partitions which are only 34 block smaller > than your zfs partition you're likely going to need to dump and restore > the entire pool as it won't accept vdevs smaller than the original. > Adding "-a 1M" to your gpart command when partitioning disks, regardless of their use, is very handy for this. It starts the first partition at 1MB, which gives you enough slack to increase the size of the freebsd-boot partition as needed. :) You can even add a freebsd-boot partition to make a data pool bootable as root with that amount of slack. :D Went through that at home. And ZFS has reserved a few MB from the end of the device you give it to allow for replacement drives that aren't the exact same size (in sectors or bytes) for awhile now (maybe since the 9.x days?). Cheers, Freddie Typos courtesy of my phone's keyboard.