From owner-freebsd-geom@FreeBSD.ORG Tue Jan 7 00:03:06 2014 Return-Path: Delivered-To: freebsd-geom@FreeBSD.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 1958B7F8 for ; Tue, 7 Jan 2014 00:03:06 +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 A8EEC1980 for ; Tue, 7 Jan 2014 00:03:05 +0000 (UTC) Received: from r2d2 ([82.69.141.170]) by mail1.multiplay.co.uk (mail1.multiplay.co.uk [85.236.96.23]) (MDaemon PRO v10.0.4) with ESMTP id md50007442704.msg for ; Tue, 07 Jan 2014 00:02:55 +0000 X-Spam-Processed: mail1.multiplay.co.uk, Tue, 07 Jan 2014 00:02:55 +0000 (not processed: message from valid local sender) X-MDDKIM-Result: neutral (mail1.multiplay.co.uk) X-MDRemoteIP: 82.69.141.170 X-Return-Path: prvs=1084efce83=killing@multiplay.co.uk X-Envelope-From: killing@multiplay.co.uk X-MDaemon-Deliver-To: freebsd-geom@FreeBSD.org Message-ID: <7FBCC53840FA45928B9F527EA235B632@multiplay.co.uk> From: "Steven Hartland" To: "Miroslav Lachman" <000.fbsd@quip.cz>, "Karl Pielorz" References: <52A90049.7050001@quip.cz> <18C59233568D3A475FF0D843@study64.tdx.co.uk> <52CB2915.7060602@quip.cz> Subject: Re: Is TRIM working with gmirror? Date: Tue, 7 Jan 2014 00:02:46 -0000 MIME-Version: 1.0 Content-Type: text/plain; format=flowed; charset="iso-8859-1"; reply-type=response 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 Cc: freebsd-geom@FreeBSD.org X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.17 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 07 Jan 2014 00:03:06 -0000 ----- Original Message ----- From: "Miroslav Lachman" <000.fbsd@quip.cz> To: "Karl Pielorz" Cc: Sent: Monday, January 06, 2014 10:07 PM Subject: Re: Is TRIM working with gmirror? > Karl Pielorz wrote: > [...] >>> WARNING: /ssd_db: TRIM flag on fs but disk does not confirm that it >>> supports TRIM >>> >>> The filesystem is classic UFS2. >>> >>> Is TRIM supported throught gmirror, or not? >> >> I think 8.4 is way too old for this. I have a number of 9.2 boxes - and >> even on those, TRIM doesn't propagate through gmirror *yet* (at the >> time, which is a few months ago I seem to remember reading 'It should >> work soon' - but 9.2 doesn't appear to). >> >> You can use gstat to show if any calls to BIO_DELETE are being made - i.e. >> >> gstat -d >> >> On the systems here the 'd/s' (which afaik is 'BIO_DELETE/second') >> remains stubbornly at zero :( > > Thank you for pointing me to gstat -d. d/s is really zero all the time. > >> The flipside is with decent SSD's these days TRIM isn't quite so >> important... Some may even argue that *not* issuing heaps of BIO_DELETE >> on the I/O channel is actually faster - so long as the SSD has time to >> play catchup and isn't pegged all the time, I think they may be right :-) > > The SSDs in question are holding /var/db/mysql with heavily used InnoDB > tables (grow only ibdata file, few deletes of MyISAM tables) so maybe > there are not much delete commands at all. Delete's are only support by CAM currently so if your device is not connected to a CAM based driver e.g. daX or adaX then its likely not getting through to the device. Not sure if this has been mentioned but you also need to have filesystem support, as your talking about gmirror I assume your using UFS which would need to be TRIM enabled using tunefs -t enable, see man tunefs for more info. 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.