From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Rath Date: Thu, 3 Mar 2016 11:17:30 +0100 Subject: directory instead of link for thinpools? Message-ID: <56D80F3A.4010700@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, Im using thinpool-devices for a longer time (3+ years) and thinking about a more intuitive representation in /dev/. If Im right, Thinpools are not used directly (as device), only as pool for thinpool-based devices (these with --virtualsize instead of --size). I.e. we are using "vg" as volumegroup and "pool" as thinpool, "pooldevice" a "pool" based virtual device and "standarddevice" a normal (non-thinpool) lvm-device, then following happens: - /dev/vg/pool is a link to /dev/dm-X, which is a device node, but never used directly - /dev/vg/pooldevice is also a link to /dev/dm-Y, but now it is useable directly - /dev/vg/standarddevice is also a link to /dev/dm-Z, useable directly, but not snappable like thinpool devices This is imho a bit confusing. My idea now would be to change the representation of "pool" from a link to this (never directly used) device to a directory, which includes the links to the pooldevices. Now the representation would look like this ("/" is dir, "@" is link): /dev/vg/standarddevice@ /dev/vg/pool/ /dev/vg/pool/pooldevice@ Now I tried to create this with udev-rules, but unfortunatly I didnt find any possibility to differ between standarddevices, pools and pool-based devices. Is there any possibility to recogize this for udev-rules? What do you think generally about this idea? Tfh! Oliver