I work a lot with imaged drives, meaning a do a dd-copy of the drive in question and then work on the image instead of the drive itself.For most work, I use kpartx to map the drive's partitions to a device under /dev/mapper/. What I'm wondering here is if there's a way to find which of the mapping belong to which image.Consider this:root@vyvyan:/tmp# kpartx -a -v Image1 add map loop1p1 (254:4): 0 10240 linear /dev/loop1 2048add map loop1p2 (254:5): 0 10240 linear /dev/loop1 12288add map loop1p3 (254:6): 0 52848 linear /dev/loop1 22528root@vyvyan:/tmp# kpartx -a -v Image2add map loop2p1 (254:7): 0 33508 linear /dev/loop2 2048add map loop2p2 (254:8): 0 39820 linear /dev/loop2 35556Now, let's say I forget which image went to which mapping. Is there a way to let kpartx - or the kernel, or anything else - tell me which image goes where?EDIT Also, if I accidentally rm the image-file while kpartx has added the mappings, how do you remove the mappings? kpartx wants the actual image to be present.
How to find which images belong to which /dev/loop?
loop device;disk image
losetup (the command normally used to set them up) will tell you:$ /sbin/losetup --listNAME       SIZELIMIT OFFSET AUTOCLEAR RO BACK-FILE/dev/loop0         0      0         0  0 /var/tmp/jigdo/debian-7.6.0-amd64-CD-1.isoNote that with older versions you may hat to use use -a instead of --list, and this  outputs in a different and now deprecated format.The information comes from /sys:$ cat /sys/class/block/loop0/loop/backing_file /var/tmp/jigdo/debian-7.6.0-amd64-CD-1.isoAnother, possibly more portable, option is to get it from udisks:$ udisksctl info -b /dev/loop0/org/freedesktop/UDisks2/block_devices/loop0:  org.freedesktop.UDisks2.Loop:    Autoclear:          false    BackingFile:        /var/tmp/jigdo/debian-7.6.0-amd64-CD-1.iso    SetupByUID:         1000losetup will also happily remove them for you, using the -d option. That just requires the loop device as a parameter; it doesn't care about the backing file/device.