Issue

• The iostat command is reporting many dm devices that do not exist any longer. They did un-present several LUNs, and did it cleanly. The devices do not show in /dev, but they do see them under sys/block. They do still have aliases in the multipath config file for the devices that are no longer present. How do I tell what device is what?
• PV is created on top of dm device. How to find which dm device maps to which block device?
• How to find which dm-* device maps to which LVM logical volume?
• It's difficult to find which dm-* device maps to which LVM if there are too many dm-* devices in the system. How to find the mapping relationship between them?
• Need to map logical volumes to physical devices
• Need to find out which LVs are on which disks