How to: Device Mapper Number to LV Name

It is often confusing when device mapper number appears while troubleshooting in place of logical volume names. Device mapper numbers are like dm-1, dm-2 ..., while logical volume names are given names. There is a simple command available to find out which dm belongs to which lv. 

dmsetup ls

This would show something similar to the following:

# dmsetup ls
vg0-tp0-tpool (253:4)
vg0-tp0_tdata (253:3)
vg0-tp0_tmeta (253:2)
vg0-qcow2 (253:9)
vg0-tp0 (253:5)

It says dm-5 is /dev/vg0/tp0 or dm-9 is /dev/vg0/qcow2. The number after : would extend the dm number in /dev.
  • lvm, device mapper, dmsetup, dev, linux
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