From owner-freebsd-fs@FreeBSD.ORG Fri Nov 29 22:26:19 2013 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 277DE6F2 for ; Fri, 29 Nov 2013 22:26:19 +0000 (UTC) Received: from mail1.multiplay.co.uk (mail1.multiplay.co.uk [85.236.96.23]) (using TLSv1 with cipher RC4-MD5 (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id B434C12C8 for ; Fri, 29 Nov 2013 22:26:18 +0000 (UTC) Received: from r2d2 ([82.69.179.241]) by mail1.multiplay.co.uk (mail1.multiplay.co.uk [85.236.96.23]) (MDaemon PRO v10.0.4) with ESMTP id md50006876036.msg for ; Fri, 29 Nov 2013 22:26:16 +0000 X-Spam-Processed: mail1.multiplay.co.uk, Fri, 29 Nov 2013 22:26:16 +0000 (not processed: message from valid local sender) X-MDDKIM-Result: neutral (mail1.multiplay.co.uk) X-MDRemoteIP: 82.69.179.241 X-Return-Path: prvs=10451ca0e0=killing@multiplay.co.uk X-Envelope-From: killing@multiplay.co.uk X-MDaemon-Deliver-To: freebsd-fs@freebsd.org Message-ID: <5C60466ABFE5442690405143D7AA4695@multiplay.co.uk> From: "Steven Hartland" To: "Beeblebrox" , References: <1385723204127-5864731.post@n5.nabble.com> <67B55680E8B7491D9ED6F36ED9E28A49@multiplay.co.uk> <1385753577419-5864830.post@n5.nabble.com> <09C05F6302494B61A52C1C5065C719CE@multiplay.co.uk> <1385761744784-5864851.post@n5.nabble.com> Subject: Re: ZFS Trim Date: Fri, 29 Nov 2013 22:26:13 -0000 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=original Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.16 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 29 Nov 2013 22:26:19 -0000 ----- Original Message ----- From: "Beeblebrox" > Code in /boot/loader.conf needs to be: > vfs.zfs.trim.enabled = *1* > "0" disables trim. You don't need to enable TRIM as thats default. > Very dumb question on my part, and windows related probably but, when > searching the issue answers like this come up: > https://sort.symantec.com/public/documents/sfha/6.0.1/linux/productguides/html/virtualstore_admin/ch29s05.htm > ZFS is probably immune to this. My question is in context of > "trim.unsupported": > > kstat.zfs.misc.zio_trim.bytes: 16388096 > kstat.zfs.misc.zio_trim.success: 1668 > kstat.zfs.misc.zio_trim.unsupported: 197 > kstat.zfs.misc.zio_trim.failed: 0 The unsupported will be due a zpool in your machine which is likely created on a HDD hence doesn't support TRIM. If you enable a TRIM after writing then deleting data from the pool then you can fill the disk with random data and then delete that data to ensure all areas previously containing data is TRIM'ed. If this wasn't a large amount then I wouldnt bother. Regards Steve ================================================ This e.mail is private and confidential between Multiplay (UK) Ltd. and the person or entity to whom it is addressed. In the event of misdirection, the recipient is prohibited from using, copying, printing or otherwise disseminating it or any information contained in it. In the event of misdirection, illegible or incomplete transmission please telephone +44 845 868 1337 or return the E.mail to postmaster@multiplay.co.uk.