Hi, I've been chasing a problem now for a few weeks. I have a flaky SATA controller that fails unpredictably and upon doing so all drives attached are disconnected by the kernel. I have 2 discs on this controller which are the components of a RAID1 array. mdraid fails the disc (in its strange way) stating that one device is removed and the other is active. Apparently this is the default mdraid approach. Even though both devices are in fact failed. Regardless, the devmapper device which is supporting an LVM logical volume on top of this raid array, remains active. The logical volume is no longer listed by lvdisplay, but dmsetup -c info shows: Name Maj Min Stat Open Targ Event UUID storage.mx.vg2-shared_sun_NAS.lv1 253 2 L--w 1 1 0 LVM-Ud9pj6QE4hK1K3xiAFMVCnno3SrXaRyTXJLtTGDOPjBUppJgzr4t0jJowixEOtx7 storage.mx.vg1-shared_sun_users.lv1 253 1 L--w 1 1 0 LVM-ypcHlbNXu36FLRgU0EcUiXBSIvcOlHEP3MHkBKsBeHf6Q68TIuGA9hd5UfCpvOeo ubuntu_server--vg-ubuntu_server--lv 253 0 L--w 1 1 0 LVM-eGBUJxP1vlW3MfNNeC2r5JfQUiKKWZ73t3U3Jji3lggXe8LPrUf0xRE0YyPzSorO The device in question is 'storage.mx.vg2-shared_sun_NAS.lv1' As can be seen is displays 'open' however lsof /dev/mapper/storage.mx.vg2-shared_sun_NAS.lv1 <blank> fuser -m /dev/storage.mx.vg1/shared_sun_users.lv1 <blank> dmsetup status storage.mx.vg2-shared_sun_NAS.lv1 0 976502784 error dmsetup remove storage.mx.vg2-shared_sun_NAS.lv1 device-mapper: remove ioctl on storage.mx.vg2-shared_sun_NAS.lv1 failed: Device or resource busy dmsetup wipe_table storage.mx.vg2-shared_sun_NAS.lv1 device-mapper: resume ioctl on storage.mx.vg2-shared_sun_NAS.lv1 failed: Invalid argument and so on. Nothing appears to be attached to this device but it refuses to be removed. As a consequence I can not disable the mdraid array and can not recover the controller. Which is possible by resetting the pci slot. Currently the only possible way I have to recover this problem is to reboot the server. Please see. https://marc.info/?l=linux-raid&m=164159457011525&w=2 for the discussion regarding the same problem on the linux-raid mailing list. No progress so far, help appreciated Aidan -- dm-devel mailing list dm-devel@xxxxxxxxxx https://listman.redhat.com/mailman/listinfo/dm-devel