From owner-freebsd-fs@FreeBSD.ORG Tue Mar 24 17:11:02 2015 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id D96AFB9A; Tue, 24 Mar 2015 17:11:01 +0000 (UTC) Received: from smtp.libraryvideo.com (smtp.libraryvideo.com [144.202.216.43]) (using TLSv1.1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id A0289839; Tue, 24 Mar 2015 17:11:01 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp.libraryvideo.com (Postfix) with ESMTP id 55E3722F349; Tue, 24 Mar 2015 13:05:49 -0400 (EDT) X-Virus-Scanned: Debian amavisd-new at libraryvideo.com Received: from smtp.libraryvideo.com ([127.0.0.1]) by localhost (smtp.libraryvideo.com [127.0.0.1]) (amavisd-new, port 10024) with LMTP id SqYA46JtexQ0; Tue, 24 Mar 2015 13:05:45 -0400 (EDT) Received: from heimdall.safarimontage.com (heimdall.safarimontage.com [172.20.10.21]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by smtp.libraryvideo.com (Postfix) with ESMTPS id 20EF435F3CB; Tue, 24 Mar 2015 13:05:45 -0400 (EDT) Received: from VALKYRIE.lvc.com (172.20.1.74) by heimdall.safarimontage.com (172.20.10.21) with Microsoft SMTP Server (TLS) id 14.0.722.0; Tue, 24 Mar 2015 13:05:44 -0400 Received: from LOKI.lvc.com ([fe80::d5b5:77e5:625d:d205]) by valkyrie.lvc.com ([fe80::716a:53e0:bf7d:632f%10]) with mapi id 14.02.0328.009; Tue, 24 Mar 2015 13:05:45 -0400 From: Dale Kline To: 'Tom Evans' , Shehbaz Jaffer Subject: RE: Zoned Commands ZBC/ZAC, Shingled SMR drives, ZFS Thread-Topic: Zoned Commands ZBC/ZAC, Shingled SMR drives, ZFS Thread-Index: AQHQXQo064rMisN8t0yr6P74JAyzDJ0r6nqAgABAmYD//8NzkA== Date: Tue, 24 Mar 2015 17:05:45 +0000 Message-ID: <02F3A553C174554DA1D5EC7CEE9BDDD7011BC3E42B@loki.lvc.com> References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.10.1.113] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Cc: FreeBSD FS , grarpamp , "freebsd-hardware@freebsd.org" X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 24 Mar 2015 17:11:02 -0000 READ THE DOCUMENTATION THOROUGHLY on these SMR drives. There are serious = WRITE restrictions on these drives because of the overlapping (shingled) tr= acks. I have read over several times and am still not sure of all of the c= aveats. As Tom states below, they are to be used mainly in "WRITE ONCE, = READ MANY" environments. -----Original Message----- From: owner-freebsd-hardware@freebsd.org [mailto:owner-freebsd-hardware@fre= ebsd.org] On Behalf Of Tom Evans Sent: Tuesday, March 24, 2015 12:39 PM To: Shehbaz Jaffer Cc: FreeBSD FS; grarpamp; freebsd-hardware@freebsd.org Subject: Re: Zoned Commands ZBC/ZAC, Shingled SMR drives, ZFS On Tue, Mar 24, 2015 at 12:47 PM, Shehbaz Jaffer wrote: > Hi, > > I was wondering what cost advantage do SMR drive provide as compared=20 > to normal CMR drive? > > 8TB SMR drive - $ 260 > 3TB CMR (Conventional Magnetic Recording drive) - $ 105 > Purchase price is not irrelevant, but the key benefits are increased capaci= ty per disk, and reduced power usage per disk and (multiplied by the increa= se in capacity) per TB. In other words, they disks consume less power, you = need fewer of them, maybe allowing you to run fewer servers. Of course, you also need a mainly read only workload. The RAID rebuild test= from the linked review is *scary*. I wouldn't use these in ZFS raidz witho= ut plenty of disaster recovery testing - how long does it take to re-silver= the pool when you lose a disk and what is the performance characteristics = of the pool whilst it is doing so. Cheers Tom _______________________________________________ freebsd-hardware@freebsd.org mailing list http://lists.freebsd.org/mailman/= listinfo/freebsd-hardware To unsubscribe, send any mail to "freebsd-hardware-unsubscribe@freebsd.org"