From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bill Davidsen Subject: Re: split raid1 into to arrays Date: Tue, 27 Mar 2007 11:57:12 -0400 Message-ID: <46093ED8.8020201@tmr.com> References: <5d0f60990703261954l2bb8c225ocbc3cf66e868723a@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5d0f60990703261954l2bb8c225ocbc3cf66e868723a@mail.gmail.com> Sender: linux-raid-owner@vger.kernel.org To: Dirk Jagdmann Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Dirk Jagdmann wrote: > Hello experts, > > I have a raid1 array with two drives working. It /dev/md0 built from > /dev/hda and /dev/hdb. Now I'd like to split it into two array with > one drive each (and then later add spares to my two arrays again). I > know that I can remove one drive from the array with: mdadm /dev/md0 > -f /dev/hdb -r /dev/hdb , however I'm not sure what the superblock of > /dev/hdb now contains and how I could use the contents of /dev/hdb as > the starting point for my new /dev/md1 array? I did not find anything > in the manpage of mdadm which would provide me an automatic split. > > So what are your advises? > The fast way (not redundant): You can mark hdb as failed, then remove it. Then you can create a new array using hdb and a missing device. The safe way: get your additional drives, call then hdc and hdd just for discussion. add hdc to the existing array and let it rebuild, then mark hdb as failed and remove. Create a new array from hdb and hdd. I'm sure someone will tell me if I left out a step. -- bill davidsen CTO TMR Associates, Inc Doing interesting things with small computers since 1979