From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mx3.redhat.com (mx3.redhat.com [172.16.48.32]) by int-mx1.corp.redhat.com (8.12.11.20060308/8.12.11) with ESMTP id k4JDr30D000948 for ; Fri, 19 May 2006 09:53:03 -0400 Received: from py-out-1112.google.com (py-out-1112.google.com [64.233.166.180]) by mx3.redhat.com (8.13.1/8.13.1) with ESMTP id k4JDqtxF008322 for ; Fri, 19 May 2006 09:52:56 -0400 Received: by py-out-1112.google.com with SMTP id 39so857210pyu for ; Fri, 19 May 2006 06:52:55 -0700 (PDT) Message-ID: <87f94c370605190652w64f92cfl91ea9bc3d59925a3@mail.gmail.com> Date: Fri, 19 May 2006 09:52:55 -0400 From: "Greg Freemyer" Subject: Re: [linux-lvm] realtime snapshot or ? In-Reply-To: <1282.85.107.14.146.1146382053.squirrel@85.107.14.146> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_Part_64783_27512109.1148046775611" References: <1282.85.107.14.146.1146382053.squirrel@85.107.14.146> 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: To: omer@faruk.net, LVM general discussion and development ------=_Part_64783_27512109.1148046775611 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On 4/30/06, Omer Faruk Sen wrote: > > > > I have found that nbd ord drbd does similar things. But nbd just exports = a > block device (JUST ONE block device) so other machines can mount it. DRBD > is closer to what I want but I can't mount drbd on secondary (backup > machine) even as read-only You should check out drbd 0.8 and see if it still has the same restriction. 0.8 is in beta or pre-release. It is supposed to allow "active/active" environments. I believe a clustered FS like GFS is intended to be used wit= h the new functionality, but it may be that the slave can do a read-only mount. If not, you could use GFS as your filesystem and achieve your goal. The big trouble with that is locking. I'm pretty sure GFS only does file locking. Not very helpful for a DB. Greg --=20 Greg Freemyer The Norcross Group Forensics for the 21st Century ------=_Part_64783_27512109.1148046775611 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Content-Disposition: inline

On 4/30/06, Omer Faruk Sen <omer@faruk= .net> wrote:
<snip>

I have found that nbd ord drbd does similar things. But= nbd just exports a
block device (JUST ONE block device) so other machin= es can mount it. DRBD
is closer to what I want but I can't mount drbd on= secondary (backup
machine) even as read-only

You should check out dr= bd 0.8 and see if it still has the same restriction.  0.8 is in beta o= r pre-release.  It is supposed to allow "active/active" = ; environments.  I believe a clustered FS like GFS is intended to be = used with the new functionality, but it may be that the slave can do a read= -only mount.  If not, you could use GFS as your filesystem and achieve= your goal.  The big trouble with that is locking.  I'm pretty su= re GFS only does file locking.  Not very helpful for a DB.

Greg
--
Greg Freemyer
The Norcross Group
F= orensics for the 21st Century ------=_Part_64783_27512109.1148046775611--