Thanks Oliver, useful checks! -----Original Message----- To: ceph-users Subject: Re: [ceph-users] ceph-volume lvm cannot zap??? Hi, we have also seen such cases, it seems that sometimes (when the controller / device is broken in special ways), device mapper keeps the volume locked. You can check as follows: 1) Check if lvs / pvs / vgs show some undefined device. In that case, you may have to flush the lvmeta cache: pvscan --cache Check again if zapping works after this, if not, continue. 2) Check major and minor number of the device: $ ls -la /dev/sdi brw-rw----. 1 root disk 66, 96 13. Jan 18:14 /dev/sdi => In this case, it would be 66:96 3) Check if device mapper still has it locked: $ dmsetup ls --tree ... ceph--1f6780e6--b120--4876--b674--aa3337847114-osd--block--1325f49b--fea d--40ba--957e--ec6b2968d456 (253:1) └─ (66:96) ... => In this case, it is still mapped! 4) Attempt to remove it: $ dmsetup remove ceph--1f6780e6--b120--4876--b674--aa3337847114-osd--block--1325f49b--fea d--40ba--957e--ec6b2968d456 => If this fails, you may have to use --force (if the disk does not accept any read/write anymore, this might happen). Please make absolutely sure this is the correct disk before using force. 5) If after this, lvs / pvs / vgs show some undefined device, you may have to flush the lvmeta cache: pvscan --cache Latest after these steps, zapping should work, at least we never encountered anything worse (apart from hangs with a broken RAID controler firmware, where we needed to eject and reinsert the disk and rescan devices to make the controller lock go away). Cheers, Oliver