From owner-freebsd-questions@freebsd.org Wed Sep 16 08:18:45 2015 Return-Path: Delivered-To: freebsd-questions@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 51A7E9CDB12 for ; Wed, 16 Sep 2015 08:18:45 +0000 (UTC) (envelope-from kraduk@gmail.com) Received: from mail-wi0-x232.google.com (mail-wi0-x232.google.com [IPv6:2a00:1450:400c:c05::232]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id DBEAB1B86 for ; Wed, 16 Sep 2015 08:18:44 +0000 (UTC) (envelope-from kraduk@gmail.com) Received: by wicge5 with SMTP id ge5so62566350wic.0 for ; Wed, 16 Sep 2015 01:18:43 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=U5t5Rt+I2NMf5ryXB1QAfBLfhxDKsGcS3kKfktZ/eyg=; b=lm0aF21LCNEDjnrvs4CfsvV0OL823EtEOEMJ8irPlH/5byxHgttBhllpIDFma5SatU Y6qybpMcLciP+Dvv/ncHCeIEb+nt0wG8ELwihTHpD7qj0hvDahPDySOLBhGv+B+lq251 nNHyW44G9VnkXXcO5RQgVsstysuViEZ+heq8sHXtvKP5vUhF3zyKoFCgeK1E786P41IY Ih/ZMwd60WeEqQRRnFmalX04vjM/C7zkA63WQdRH8yYeplp3ASkpwNNkVAYLLvRAF56s oDDfTqPWxl+FPZMAzFJSCjuMXKRR9hsbZ13iW6U20JLJEd36B0zMevrk14Phvo54QlSc 3dTw== MIME-Version: 1.0 X-Received: by 10.194.19.169 with SMTP id g9mr47639954wje.64.1442391523337; Wed, 16 Sep 2015 01:18:43 -0700 (PDT) Received: by 10.28.125.18 with HTTP; Wed, 16 Sep 2015 01:18:43 -0700 (PDT) In-Reply-To: <08306F31-955B-4710-B20B-4F2ABE0CBA56@kraus-haus.org> References: <20150829220311.c7608be1.freebsd@edvax.de> <55E45973.2050103@sneakertech.com> <55E4865B.1000104@sneakertech.com> <20150831181135.7682a810@gumby.homeunix.com> <867fnywc8i.fsf@WorkBox.Home> <08306F31-955B-4710-B20B-4F2ABE0CBA56@kraus-haus.org> Date: Wed, 16 Sep 2015 09:18:43 +0100 Message-ID: Subject: Re: Replacing Drive with SSD From: krad To: Paul Kraus Cc: FreeBSD Questions Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Content-Filtered-By: Mailman/MimeDel 2.1.20 X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 16 Sep 2015 08:18:45 -0000 a bit late to this i know but when I have under over provisioned, I did it by getting the drives to report a lower amount of storage than they have rather than using the non partitioned way of doing it. This guarantees the drives firmware knows it free space much more effectively than the partition method which doesnt mean a lot to the drive. I used something like the below just after doing a secure erase on the drive to reduce the reported size from say 120GB to 100GB (this was done from the gparted livecd, as i couldnt find out howto do it within BSD back then) hdparm -Np281323627 --yes-i-know-what-i-am-doing /dev/sdb On 10 September 2015 at 18:42, Paul Kraus wrote: > On Sep 10, 2015, at 11:00, Brandon J. Wandersee < > brandon.wandersee@gmail.com> wrote: > > > Leaving blocks unpartitioned doesn't mean those blocks won't be written > > to; it just ensures that a certain amount of space (and so a certain > > number of blocks/cells) must always be free, forcing writes to be sprea= d > > across different physical portions of the disk in a relatively even > > manner. It's my understanding that this over-provisioning isn't > > exactly necessary in most SSDs nowadays. It just serves as a stronger > > guarantee than entrusting everything to a drive's firmware. > > Each SSD model has some amount of over provisioning built in. The more > expensive, Enterprise grade SSDs have more (in many cases much more) than > the cheaper consumer units. So based on the performance you need and the > SSD you have, it is still prudent to manually over provision with > unpartitioned space. > > Note that some vendors will tell you about their over provisioning and > others don=E2=80=99t. > > -- > Paul Kraus > paul@kraus-haus.org > > _______________________________________________ > freebsd-questions@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to " > freebsd-questions-unsubscribe@freebsd.org" >