From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Mon, 30 Oct 2017 22:56:24 +0000 From: Alasdair G Kergon Message-ID: <20171030225624.GA26719@agk-dp.fab.redhat.com> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: Subject: Re: [linux-lvm] When and why vgs command can change metadata and incur old metadata to be backed up? 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" Content-Transfer-Encoding: 7bit To: Eric Ren Cc: LVM general discussion and development On Mon, Oct 30, 2017 at 02:06:45PM +0800, Eric Ren wrote: > """ > contents = "Text Format Volume Group" > version = 1 > > description = "Created *before* executing 'vgs'" > """ > I'm wondering when and why the new backups will be created by reporting > command like vgs? Very simply if the metadata the command has just read in does not match the last backup stored in the local filesystem and the process is able and configured to write a new backup. The command that made the metadata change might not have written a backup if it crashed, was configured not to write backups, was running with the filesystem readonly (e.g. booted into a recovery mode), ran on a different node in a cluster, ran as part of an installer that chose not to give you any metadata backups, performed metadata recovery etc. (Plus an old release had a bug where the checking went wrong and it made a backup every time even though nothing had actually changed.) Alasdair