From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Rath Date: Wed, 05 Feb 2014 10:44:50 +0100 Subject: naming problem on cached devices Message-ID: <52F20812.8010305@mglug.de> List-Id: To: lvm-devel@redhat.com MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Hi list, i have a little problem here using (not only happen on lvm ;-) ) cached devices: I.e. i have a ssd named /dev/ssd and a standard disk /dev/sda1 to be cached. If I now create i.e. a device /dev/mapper/cache0 (done by dmsetup at the mom) and create there a pv, this pv exists twice (at ssd and sda). If I then create a vg based on ssd, this vg exists twice, too. This happens i.e. for flashcache device, too. Is there a mechanism to avoid this doubling in an easy way? I know, you can blind out devices with a filter argument in lvm.conf, but maybe there are better possibilities. There is another interesting case: If i want to cache an *existing* pv, is it possiblie to change the *name* of this pv in a vg in a dynamic way? I.e. if the vg "myvg" consists on /dev/sdc1, if now i create a cache-device /dev/mapper/sdc1_cached, how can i transfer this name into myvg instead of the original sdc1? Or is this the wrong question? Tfh! Oliver