Hi, > Since the /dev/dm-x has been created, I don't understand what it waits > udev to do? > Just waits udev rules to create device symbol links? Although the /dev/dm-26 is visible, but the device seems not ready in kernel. [root@iZuf6dbyd7ede51sykedamZ ~]# dmsetup udevcookies Cookie Semid Value Last semop time Last change time 0xd4d0b57 225214464 2 Fri Apr 12 17:33:14 2019 Fri Apr 12 17:33:14 2019 [root@iZuf6dbyd7ede51sykedamZ ~]# dmsetup info /dev/dm-26 Device dm-26 not found Command failed. [root@iZuf6dbyd7ede51sykedamZ ~]# ls -l /dev/dm-26 brw-rw---- 1 root disk 252, 26 4月 12 17:33 /dev/dm-26 Regards. _______________________________________________ linux-lvm mailing list linux-lvm@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/