From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx1.redhat.com (ext-mx10.extmail.prod.ext.phx2.redhat.com [10.5.110.14]) by int-mx12.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id oAUFfYL5032650 for ; Tue, 30 Nov 2010 10:41:34 -0500 Received: from smtp12.tagonline.com (nat199.nat.tagonline.com [207.111.79.199]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id oAUFfL6p001085 for ; Tue, 30 Nov 2010 10:41:22 -0500 Received: from taco.int.tagonline.com (localhost.localdomain [127.0.0.1]) by localhost.localdomain for (8.13.1/8.12.8/muffin_cf_1.0) with ESMTP id oAUFfL89015394 for ; Tue, 30 Nov 2010 10:41:21 -0500 Received: (from news@localhost) by taco.int.tagonline.com (8.13.1/8.13.1/Submit) id oAUFfLIm015393 for linux-lvm@redhat.com; Tue, 30 Nov 2010 10:41:21 -0500 From: Andrew Gideon Date: Tue, 30 Nov 2010 15:41:21 +0000 (UTC) Message-ID: References: <4CF3F7A0.2080108@rjl.com> <4CF4A472.20107@rjl.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: Re: [linux-lvm] Q: LVM over RAID, or plain disks? A:"Yes" = best of both worlds? Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" To: linux-lvm@redhat.com On Tue, 30 Nov 2010 14:34:05 +0700, hansbkk wrote: > So here's a summary of steps, please confirm: > - create a snapshot of a given volume - create a new RAID1 mdN between > that and a physical partition (blank?) - let that get sync'd up - > break the RAID (fail the partition?), remove the drive - delete the > snapshot I'm having some difficulty following this thread, so perhaps I've missed some other aspect to this. But the above makes it seem like you simply wish to transport snapshots. Why not use something as straightforward as dd for this rather than RAID1? RAID1 tools (mdadm, drbd, etc.) have the benefit of keeping volumes in sync over time. But the above process describes a synchronization over a single instant (the instant of the snapshot being taken). So why bother with the extra work/capability/ complexity? I'm also puzzled by something you wrote in your very first message on this thread: "the hard-linked filesystems on FILER-B require full filesystem cloning with block-level tools rather than file-level copying or sync'ing." Why? rsync -H handles cloning of hard links (though at a performance cost). - Andrew