From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from jeltz.chrissie.net (vpn-6-7.fab.redhat.com [10.33.6.7]) by pobox.fab.redhat.com (8.13.1/8.13.1) with ESMTP id m188VIJw002525 for ; Fri, 8 Feb 2008 03:31:18 -0500 Message-ID: <47AC1355.1090607@redhat.com> Date: Fri, 08 Feb 2008 08:31:17 +0000 From: Patrick Caulfeld MIME-Version: 1.0 Subject: Re: [linux-lvm] Docs on clustered option of vgcreate References: <9BB520CB-6D8D-49A5-BF38-92BEB8875FDF@redhat.com> In-Reply-To: Content-Transfer-Encoding: 8bit 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="utf-8" To: LVM general discussion and development Gerrard Geldenhuis wrote: > Excellent, thanks for the answer, that makes it a lot clearer. > > > > So coupled with exclusion lists etc.. I could have multiple machines > connect to one LUN and each have its own logical volume. Is there a > concept of a �master� in the cluster or does it work in the same way as > tcp with an exponential backoff when the metadata is locked by a host > for changing. I am assuming that cluster aware locking would allow > server-a to create a new lv but not simalteneosly allowing server-b to > create a new lv too. > > > > I know should be experimenting with this but will ask in the mean time > while I wait for my �test lun�. > > > > If host A creates a lv on a shared storage will it automatically be > marked as only belonging to host A or is that something you have to do > by hand. I read somewhere in the man pages about tags that you need to > add to achieve such things. > Locking in CLVM is exclusive and there's no back off. There is no reason for it, creating an LVM doesn't take very long and is done from a command-line. Host 'b' will simply wait until host 'a' has finished its job. If you need to mark LVs to be exclusive to a node you will need to use tags to define which node is allowed access