From owner-freebsd-questions@FreeBSD.ORG Wed Jan 26 20:13:21 2011 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 956F3106566C for ; Wed, 26 Jan 2011 20:13:21 +0000 (UTC) (envelope-from christer.solskogen@gmail.com) Received: from mail-pv0-f182.google.com (mail-pv0-f182.google.com [74.125.83.182]) by mx1.freebsd.org (Postfix) with ESMTP id 67EBF8FC15 for ; Wed, 26 Jan 2011 20:13:21 +0000 (UTC) Received: by pvc22 with SMTP id 22so148677pvc.13 for ; Wed, 26 Jan 2011 12:13:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc:content-type:content-transfer-encoding; bh=9Tmpr5orqzuEObRmMdq6SWSsXEv9AvsT+406ZTNxU7E=; b=XH6SYUJmQt/dwXj002jEQEzXHfQL1IWvf2WBVADppOiRNyoHZVCXdcxYvLphS+cy61 gkohCRA2pKa31Q3r//pPcoVwP4HJh1TZP+fE2lf8okoYJxv6kWDyEJGV61sQUEmmIQk0 eOo3QAU6LHyKO+N5rrCjYfFb/n+qTB9em8sxI= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-type:content-transfer-encoding; b=NUHtfgZWoLh3d6S1MVtL52p+Bhe6YT1ZGvoaqyMxlRvDomor/lLBkT5vdYVbogFp70 5lqOD4xS6PwJkhQO8CpnpQMwM6AAolztkbHa0K7j0RmHdpnn9iw7GV0W5YNVtbgLA3Vi nzqr4ba2JqSMS+IAV1WsanWDVuV1S5L8vf+/s= Received: by 10.142.156.18 with SMTP id d18mr874014wfe.69.1296072800963; Wed, 26 Jan 2011 12:13:20 -0800 (PST) MIME-Version: 1.0 Received: by 10.142.72.2 with HTTP; Wed, 26 Jan 2011 12:12:57 -0800 (PST) In-Reply-To: <20110126195800.GM75125@dan.emsphone.com> References: <4D3FDE82.4000105@mail.zedat.fu-berlin.de> <20110126195800.GM75125@dan.emsphone.com> From: Christer Solskogen Date: Wed, 26 Jan 2011 21:12:57 +0100 Message-ID: To: Dan Nelson Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Cc: "O. Hartmann" , freebsd-questions@freebsd.org Subject: Re: FreeBSD 9/ZFS: Striped Pool (2 disks) migrating to mirror (onto additional disk) 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: Wed, 26 Jan 2011 20:13:21 -0000 On Wed, Jan 26, 2011 at 8:58 PM, Dan Nelson wrote= : > In the last episode (Jan 26), Christer Solskogen said: >> On Wed, Jan 26, 2011 at 9:42 AM, O. Hartmann wrote: >> > My question is: is it possible to migrate the two-disk pool without da= ta >> > loss into a mirrored pool by adding the one 2TB-disk? >> >> No, you cant create a two-way mirror of three disks with ZFS. The only w= ay >> of doing what you want by creating a gmirror (or by hardware raid) of th= e >> two 1TB disks. > > You can, if you partition the 2tb disk into two smaller volumes, each the > same size as one of the 1tb disks, then add one of those as a mirror of e= ach > original disk. =A0You'll end up with two mirrored vdevs in the pool. > Performance probably won't be as good as a real mirror, though, since zfs > doesn't know that two of its physical disks share a spindle. > Rememer that he also asked to do this without data loss. As far as I know you cant remove devices from a vdev. If he is willing to accept data loss there are a lots of ways of doing it. --=20 chs,