From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Evans Subject: Re: RAID10 - Ensure mirrors aren't on same JBOD Date: Mon, 26 Apr 2010 14:30:50 -0700 Message-ID: References: <444163.38039.qm@web65406.mail.ac4.yahoo.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <444163.38039.qm@web65406.mail.ac4.yahoo.com> Sender: linux-raid-owner@vger.kernel.org To: Andrew Klaassen Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On Mon, Apr 26, 2010 at 1:20 PM, Andrew Klaassen w= rote: > --- On Mon, 4/26/10, Michael Evans wrote: > >> Or write your own program to generate mdadm headers on >> uninitialized devices.=A0 Or if it's just a one time thing, >> write the headers, stop the array, make sure it says what >> you want, and then force a resync before writing any data. > > So the headers determine which disks mirror which disks? > > Does that mean that if I ordered my disks correctly on the --create c= ommandline, I could depend on all of the data being ordered the way tha= t some of the data is? =A0I.e. if I figured out which two disks were mi= rroring each other, I would know that they'd always mirror each other a= s long as I didn't update the array metadata in any way? > > Thanks. > > Andrew > > > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid"= in > the body of a message to majordomo@vger.kernel.org > More majordomo info at =A0http://vger.kernel.org/majordomo-info.html > Logically that is a valid assumption. The meta-data identifies the devices and describes the device storage layout. If you pop in any older metadata devices with a newer kernel and/or version of mdadm the old layout must still be supported so that the data can be accessed. Why would anyone want to bother moving already written data without a reshape command of some kind? -- To unsubscribe from this list: send the line "unsubscribe linux-raid" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html