From owner-freebsd-fs@freebsd.org Sun Apr 12 11:54:19 2020 Return-Path: Delivered-To: freebsd-fs@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 AEFEF2BB43B for ; Sun, 12 Apr 2020 11:54:19 +0000 (UTC) (envelope-from pen@lysator.liu.se) Received: from mail.lysator.liu.se (mail.lysator.liu.se [130.236.254.3]) (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 490VXW3jMHz427x; Sun, 12 Apr 2020 11:54:19 +0000 (UTC) (envelope-from pen@lysator.liu.se) Received: from mail.lysator.liu.se (localhost [127.0.0.1]) by mail.lysator.liu.se (Postfix) with ESMTP id A33F640010; Sun, 12 Apr 2020 13:54:17 +0200 (CEST) Received: by mail.lysator.liu.se (Postfix, from userid 1004) id 9141E40015; Sun, 12 Apr 2020 13:54:17 +0200 (CEST) X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on bernadotte.lysator.liu.se X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED,AWL autolearn=disabled version=3.4.2 X-Spam-Score: -1.0 Received: from [IPv6:2001:9b1:28ff:d901:f4ee:5e2b:488:2842] (unknown [IPv6:2001:9b1:28ff:d901:f4ee:5e2b:488:2842]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.lysator.liu.se (Postfix) with ESMTPSA id 3D1C440010; Sun, 12 Apr 2020 13:54:17 +0200 (CEST) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 13.0 \(3608.60.0.2.5\)) Subject: Re: ZFS server has gone crazy slow From: Peter Eriksson In-Reply-To: <575c01de-b503-f4f9-2f13-f57f428f53ec@FreeBSD.org> Date: Sun, 12 Apr 2020 13:54:16 +0200 Cc: Andriy Gapon Content-Transfer-Encoding: quoted-printable Message-Id: References: <2182C27C-A5D3-41BF-9CE9-7C6883E43074@distal.com> <20200411174831.GA54397@fuz.su> <6190573D-BCA7-44F9-86BD-0DCBB1F69D1D@distal.com> <6fd7a561-462e-242d-5057-51c52d716d68@wp.pl> <7AA1EA07-6041-464A-A39A-158ACD1DC11C@distal.com> <575c01de-b503-f4f9-2f13-f57f428f53ec@FreeBSD.org> To: freebsd-fs X-Mailer: Apple Mail (2.3608.60.0.2.5) X-Virus-Scanned: ClamAV using ClamSMTP X-Rspamd-Queue-Id: 490VXW3jMHz427x X-Spamd-Bar: ----- Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-6.00 / 15.00]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; REPLY(-4.00)[] X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 12 Apr 2020 11:54:19 -0000 Hmm. By =E2=80=9Cancient=E2=80=9D pool version - are you thinking of the = one used during FreeBSD 11.0-11.1 days? That was what we were using at = the time when we tested =E2=80=9Czfs destroy -r foo@bar=E2=80=9D vs = =E2=80=9Czfs destroy -rd foo@bar=E2=80=9D and found that =E2=80=9C-d=E2=80= =9D was much quicker. (We=E2=80=99re now at 11.3 and 12.1 and that whole snapshot cleaning = script is completely rewritten and uses a custom =E2=80=9Czfs=E2=80=9D = binary instead that can look at custom user properties to decided which = snapshots to delete and not and is much more efficient in general.) - Peter > Note, however, that unless you have a very ancient pool version = destroying a > snapshot means that the snapshot object is removed and all blocks = belonging to > the snapshot are queued for freeing. Their actual freeing is done > asynchronously ("in background") and can be spread over multiple TXG = periods. > That's done regardless of whether -d was used. >=20 > --=20 > Andriy Gapon