how to boot from gzip image file (*.img.gz)

[lstraath]

I'm not sure i understand your question, but it looks like you made a img.gz file of a installed OS with a cloning tool and want to boot a machine from that img.gz file. If this is the case this will probebly not work because depending on the drivers and setup available in the operating system you cloned. booting from a img.gz file most of the time has the limitation that you can not write to the filesystem so it has to be a like a live cd (read only) setup or like a live cd with a aditional ram disk for write operations. In other words you need to build/configure your OS for this usage. If you have something that works like the gparted.iso.gz file for instance you could load it with memdisk. You can load img iso img.gz and iso.gz files with memdisk the gz part only means it is compressed so less transfer time.