Hallo I can not remove an unused LUN , because devicemapper is inconsistent under /sys/block. Red Hat Enterprise Linux Server release 5.5 (Tikanga) Linux xxxxxxx 2.6.18-194.el5 #1 SMP Tue Mar 16 21:52:39 EDT 2010 x86_64 x86_64 x86_64 GNU/Linux device-mapper-multipath-0.4.7-34.el5 we have two hosts (MASTER,SLAVE) , which are connected to a shared storage (EMC SAN and SRDF) with two equal sized disks. One of the disk contains a Logical Volume in one Volume Group. we wanted to migrate ("move") data from disk1 to disk2 , and remove disk1 afterwards. MASTER SLAVE disk1 (vg01/lvdata) <-srdf-> disk3 (vg01/lvdata) disk2 (empty) <-srdf-> disk4 (empty) On MASTER we "move" disk1 to disk2 with following commands. Because of the SRDF mirror disk3 is copied simultaneous to disk4. CODE "move" script # mirror pvcreate /dev/disk2 vgextend vg01 /dev/disk2 lvconvert -m1 --mirrorlog core /dev/vg01/lvdata /dev/disk2 # split lvconvert -m0 --mirrorlog core /dev/vg01/lvdata /dev/disk1 vgreduce vg01 /dev/disk1 pvremove /dev/disk1 The "move" process runs without error. On MASTER disk1 can be removed without error. On SLAVE removing disk3 gives an error like powermt remove dev=disk3 Cannot remove device that is in use: disk3 ( in real /dev/disk3 is /dev/emcpower$(belonging disk3 ) i analyzed the /sys filesystem on SLAVE and saw , that vg01-lvdata is blocks by /dev/disk3. find /sys -name '*disk3*' -ls 29486 0 lrwxrwxrwx 1 root root 0 Jul 27 09:10 /sys/block/dm-9/slaves/disk3 -> ../../../block/disk3 ls -l /dev/mapper/vg01-lvdata brw-rw---- 1 root disk 253, 9 Jul 27 09:09 /dev/mapper/vg01-lvdata My assumption is that SLAVE reconfigures the device-mapper not correct, when doing the "move" operations on MASTER. How can I reconfigure the device-mapper stuff on SLAVE to avoid an reboot ? A bit complex, but i hope i could make the problem clear to you. regards bernd -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel