From nobody Fri Aug 02 21:05:06 2024 X-Original-To: fs@mlmmj.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mlmmj.nyi.freebsd.org (Postfix) with ESMTP id 4WbJJG3b4Tz5R9wY for ; Fri, 02 Aug 2024 21:05:18 +0000 (UTC) (envelope-from SRS0=DZX9=PB=quip.cz=000.fbsd@elsa.codelab.cz) Received: from elsa.codelab.cz (elsa.codelab.cz [94.124.105.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 4WbJJF2Hjxz4TLm for ; Fri, 2 Aug 2024 21:05:17 +0000 (UTC) (envelope-from SRS0=DZX9=PB=quip.cz=000.fbsd@elsa.codelab.cz) Authentication-Results: mx1.freebsd.org; dkim=pass header.d=quip.cz header.s=private header.b=0cNAid48; dkim=pass header.d=quip.cz header.s=private header.b=ZEAFG+4I; dmarc=none; spf=none (mx1.freebsd.org: domain of "SRS0=DZX9=PB=quip.cz=000.fbsd@elsa.codelab.cz" has no SPF policy when checking 94.124.105.4) smtp.mailfrom="SRS0=DZX9=PB=quip.cz=000.fbsd@elsa.codelab.cz" Received: from elsa.codelab.cz (localhost [127.0.0.1]) by elsa.codelab.cz (Postfix) with ESMTP id 5B6CDD78B8 for ; Fri, 2 Aug 2024 23:05:08 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quip.cz; s=private; t=1722632708; bh=21xEfZpZX/Wu0lzX179uV49plre0RsCHPtET+HuWGUI=; h=Date:To:From:Subject; b=0cNAid488mSx1oOcC6AU2R/3T8AFW+EAYZRI+5KUF5Gr6ldND9t5FFZpLWq5XZXJr Eev9OFtDp/aKHxMxR/5jiBl1q9FCzA6SVInVOW8J1+GXOmq04yek4damJWDh88sVxk qq9GUGPEWKIeLLsq7NgJ3bVn03lqCLquwDX0l43I= Received: from [192.168.145.49] (ip-89-177-27-225.bb.vodafone.cz [89.177.27.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by elsa.codelab.cz (Postfix) with ESMTPSA id 487BBD78A9 for ; Fri, 2 Aug 2024 23:05:07 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=quip.cz; s=private; t=1722632707; bh=21xEfZpZX/Wu0lzX179uV49plre0RsCHPtET+HuWGUI=; h=Date:To:From:Subject; b=ZEAFG+4IO5dvX8LWm78IhcRxKV8vNML9wvWRuya5fsuIkwljIjEm3/HLx7DFwAPnA 1ruqfGQVJ1BkkwDSeVt4iyMnd8QWm+gmsSfT06PXWKVF4pUmfuuYDlxCUWP0BhVPjX hLqFKPBaGL7A37XAYzYPwE1EDVDDIzaCABit7FuM= Message-ID: <181aa62d-a940-4bd1-a057-89766f095edf@quip.cz> Date: Fri, 2 Aug 2024 23:05:06 +0200 List-Id: Filesystems List-Archive: https://lists.freebsd.org/archives/freebsd-fs List-Help: List-Post: List-Subscribe: List-Unsubscribe: Sender: owner-freebsd-fs@FreeBSD.org MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: fs@FreeBSD.org Content-Language: en-US From: Miroslav Lachman <000.fbsd@quip.cz> Subject: Inconsistency between space used by ZFS snapshots reported by zfs list Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Spamd-Bar: -- X-Spamd-Result: default: False [-2.98 / 15.00]; NEURAL_HAM_MEDIUM(-1.00)[-1.000]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.99)[-0.987]; FORGED_SENDER(0.30)[000.fbsd@quip.cz,SRS0=DZX9=PB=quip.cz=000.fbsd@elsa.codelab.cz]; R_DKIM_ALLOW(-0.20)[quip.cz:s=private]; MIME_GOOD(-0.10)[text/plain]; XM_UA_NO_VERSION(0.01)[]; R_SPF_NA(0.00)[no SPF record]; RCVD_VIA_SMTP_AUTH(0.00)[]; RCPT_COUNT_ONE(0.00)[1]; DMARC_NA(0.00)[quip.cz]; MIME_TRACE(0.00)[0:+]; ASN(0.00)[asn:42000, ipnet:94.124.104.0/21, country:CZ]; MID_RHS_MATCH_FROM(0.00)[]; ARC_NA(0.00)[]; MLMMJ_DEST(0.00)[fs@FreeBSD.org]; FROM_NEQ_ENVFROM(0.00)[000.fbsd@quip.cz,SRS0=DZX9=PB=quip.cz=000.fbsd@elsa.codelab.cz]; FROM_HAS_DN(0.00)[]; RCVD_TLS_LAST(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; TO_MATCH_ENVRCPT_ALL(0.00)[]; TO_DN_NONE(0.00)[]; PREVIOUSLY_DELIVERED(0.00)[fs@freebsd.org]; DKIM_TRACE(0.00)[quip.cz:+] X-Rspamd-Queue-Id: 4WbJJF2Hjxz4TLm Many times it happened to me that I was looking for where the used space in the pool were allocated and I couldn't get the right result. Listing "zfs list -o space" lists info that snapshots are taking up the most space, but when I list the snapshots for a given filesystem (zfs list -r -t snapshot), the sum of the occupied space does not match previously reported used size. # zfs list -o space ssdtank1/vol1/db/postgres NAME AVAIL USED USEDSNAP USEDDS USEDREFRESERV USEDCHILD ank1/vol1/db/postgres 21.8G 169G 102G 67.0G 0B 0B # zfs list -H -p -r -t snapshot tank1/vol1/db/postgres | awk 'BEGIN { used=0 } { used=used+$2 } END { print used/1024/1024/1024"GB" }' 41.9309GB USEDSNAP from zfs list -o space: 102 G sum of snapshots sizes: 41.9309 GB Why it doesn't match? What is the real space used by snapshots? zfs list -o space or the sum of snapshots sizes listed by zfs list -r -t snapshot? The machine is FreeBSD 13.3-p4 amd64. Kind regards Miroslav Lachman