On 01/16/2014 02:32 AM, Paul B. Henson wrote: >> Anatoly Pugachev >> Sent: Wednesday, January 15, 2014 12:25 PM >> >>> the /dev/mapper/.. devices are for internal use only. >> >> If so, how come most commands use it (df, mount, findmnt, etc..) and >> not /dev/vg/vol notation? > > Because /dev/vg/vol is just a symlink to /dev/mapper/vg-vol, and mount > dereferences it and uses the authoritative name when it actually mounts it. This applies only if the symlinks/nodes are created directly with libdevmapper - which is the old classical way. If udev is used to manage /dev content for dm/lvm devices then the /dev/vg/vol is a symlink to /dev/dm-X (also /dev/mapper/vg-vol is a symlink to /dev/dm-X). And dm-X is not a stable name - it can be different across reboots and activation/deactivation cycle (hence it's never used in scripts etc.). So you have to be very careful when dereferencing symlinks. As for mount, findmnt and other utilities from util-linux - they all use one common code which can handle this situation (e.g. if you call "findmnt /dev/vg/vol", it shows you /dev/mapper/vg-vol on output, not the dm-X the /dev/vg/vol is referencing actually). -- Peter _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
