Hi Marius! the /dev/mapper/.. devices are for internal use only. This is needed, because the thinPOOL is a device logical between vg and lv, which is represented with help of these special devices. Normally you should alway use the /dev/vg/lv name scheme for you own lvm-devices. Nevertheless, if you would persist to use /dev/mapper/ pathes, you can create the path with /dev/mapper/<vg>-<lv>. Note: If you lv-name includes some "-", they will be doubled in /dev/mapper notation for differentiating to the "-", which separates vg and lv name. I.e. you LV is name my-own-lv and your VG is mariusvg, then you can find the (thintpool-) device under /dev/mapper/mariusvg-my--own--lv and (better) as link /dev/mariusvg/my-own-lv. There is a point you have unfortunatly to use the /dev/mapper-notation: If you need i.e. kpartx for creating subdevices (i.e. the lv includes a virtual windows disk with partitions), then the temporalily created names are only accessible via /dev/mapper. The other created metadevices for thinpool-managment you should never touch. Hth, Oliver On 15.01.2014 09:19, Marius Vollmer wrote: > Hi, > > when looking at the udev properties of a device mapper node, how can I > decide whether this is a block device that the user can use for creating > filesystems on, etc? > > For example, when creating a thinly provisioned logical volume with these > steps > > # vgcreate TEST /dev/loop1 > # lvcreate TEST --thinpool pool -L 80 > # lvcreate -T TEST/pool -n thin -V 100 > > I end up with a lot of devices: > > # ls /dev/mapper/TEST-* > /dev/mapper/TEST-pool /dev/mapper/TEST-pool_tmeta /dev/mapper/TEST-thin > /dev/mapper/TEST-pool_tdata /dev/mapper/TEST-pool-tpool > > How can a program tell that only /dev/mapper/TEST-thin can really be > used as a block device, and the rest should be ignored? > > Is there a way to do this by looking at "udevadm info", for example? > > (What seems to work is skipping all nodes that have > DM_UDEV_IGNORE_DISK_RULES_FLAG set to true. Is this maybe even > documented somewhere?) > > Thanks! > > _______________________________________________ > 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/ _______________________________________________ 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/
