From owner-freebsd-stable@freebsd.org Thu May 6 00:01:25 2021 Return-Path: Delivered-To: freebsd-stable@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 A174C628911; Thu, 6 May 2021 00:01:25 +0000 (UTC) (envelope-from yuripv@FreeBSD.org) Received: from smtp.freebsd.org (smtp.freebsd.org [96.47.72.83]) (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 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "R3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4FbDJP4HQCz4tLf; Thu, 6 May 2021 00:01:25 +0000 (UTC) (envelope-from yuripv@FreeBSD.org) Received: from [192.168.1.12] (unknown [91.240.124.245]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) (Authenticated sender: yuripv) by smtp.freebsd.org (Postfix) with ESMTPSA id E4CCD23539; Thu, 6 May 2021 00:01:24 +0000 (UTC) (envelope-from yuripv@FreeBSD.org) Subject: Re: zpool list -p 's FREE vs. zfs list -p's AVAIL ? FREE-AVAIL == 6_675_374_080 (199G zroot pool) To: Mark Millard , freebsd-current , FreeBSD-STABLE Mailing List References: From: Yuri Pankov Message-ID: <34521f0b-a7a1-1743-244a-4149e72911a0@FreeBSD.org> Date: Thu, 6 May 2021 03:01:07 +0300 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:78.0) Gecko/20100101 Thunderbird/78.10.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.34 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, 06 May 2021 00:01:25 -0000 Mark Millard via freebsd-current wrote: > Context: > > # gpart show -pl da0 > => 40 468862048 da0 GPT (224G) > 40 532480 da0p1 efiboot0 (260M) > 532520 2008 - free - (1.0M) > 534528 25165824 da0p2 swp12a (12G) > 25700352 25165824 da0p4 swp12b (12G) > 50866176 417994752 da0p3 zfs0 (199G) > 468860928 1160 - free - (580K) > > There is just one pool: zroot and it is on zfs0 above. > > # zpool list -p > NAME SIZE ALLOC FREE CKPOINT EXPANDSZ FRAG CAP DEDUP HEALTH ALTROOT > zroot 213674622976 71075655680 142598967296 - - 28 33 1.00 ONLINE - > > So FREE: 142_598_967_296 > (using _ to make it more readable) > > # zfs list -p zroot > NAME USED AVAIL REFER MOUNTPOINT > zroot 71073697792 135923593216 98304 /zroot > > So AVAIL: 135_923_593_216 > > FREE-AVAIL == 6_675_374_080 > > > > The questions: > > Is this sort of unavailable pool-free-space normal? > Is this some sort of expected overhead that just is > not explicitly reported? Possibly a "FRAG" > consequence? >From zpoolprops(8): free The amount of free space available in the pool. By contrast, the zfs(8) available property describes how much new data can be written to ZFS filesystems/volumes. The zpool free property is not generally useful for this purpose, and can be substantially more than the zfs available space. This discrepancy is due to several factors, including raidz parity; zfs reservation, quota, refreservation, and refquota properties; and space set aside by spa_slop_shift (see zfs-module-parameters(5) for more information).