From owner-freebsd-questions@FreeBSD.ORG Mon Nov 15 19:24:04 2010 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 822C31065672 for ; Mon, 15 Nov 2010 19:24:04 +0000 (UTC) (envelope-from wojtek@tensor.gdynia.pl) Received: from tensor.gdynia.pl (tensor.gdynia.pl [89.206.35.72]) by mx1.freebsd.org (Postfix) with ESMTP id EC2618FC15 for ; Mon, 15 Nov 2010 19:24:03 +0000 (UTC) Received: Received: from 127.0.0.1 (localhost [127.0.0.1]) by tensor.gdynia.pl (8.14.4/8.14.4) with ESMTP id oAFJO1Mr078622; Mon, 15 Nov 2010 20:24:01 +0100 (CET) (envelope-from wojtek@tensor.gdynia.pl) Received: from localhost (wojtek@localhost) by tensor.gdynia.pl (8.14.4/8.14.4/Submit) with ESMTP id oAFJO1xl078619; Mon, 15 Nov 2010 20:24:01 +0100 (CET) (envelope-from wojtek@tensor.gdynia.pl) Date: Mon, 15 Nov 2010 20:24:01 +0100 (CET) From: Wojciech Puchar To: Rob In-Reply-To: <4CE145C5.8040602@midsummerdream.org> Message-ID: References: <4CE145C5.8040602@midsummerdream.org> User-Agent: Alpine 2.00 (BSF 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-questions@freebsd.org Subject: Re: ZFS and 4k sector drives X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 15 Nov 2010 19:24:04 -0000 > work with ZFS raidz2 pools. It seems that most of the 4k sector drives are > using emulation, and reporting 512 byte sectors to the OS instead of their > native 4k size. I know someone who had an issue trying to insert one of > these drives into a running ZFS pool with other 512 byte sector drives with > bad results. ZFS use 4k blocks. assuming it actually is like that and your zfs devices are whole devices or aligned partition, there should be no difference. use camcontrol identify to check what your drive do [root@somewhere ~]# camcontrol identify ada0 pass0: ATA-8 SATA 2.x device pass0: 300.000MB/s transfers (SATA 2.x, UDMA6, PIO 8192bytes) protocol ATA/ATAPI-8 SATA 2.x device model SAMSUNG HD321KJ firmware revision CP100-10 serial number S0MQJDQP610759 WWN 5000f00db61759 cylinders 16383 heads 16 sectors/track 63 sector size logical 512, physical 512, offset 0 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ LBA supported 268435455 sectors LBA48 supported 625142448 sectors PIO supported PIO4 DMA supported WDMA2 UDMA6