Cannot clone jetson TK1 - Resolved

I’m using Jetpack 2.3.1
Following the instructions on http://elinux.org/Jetson/Cloning
I entered the jetson I want to clone into recovery mode and hooked its microusb to the uSB of the linum machine I used to flash it originally:
under ~/Downloads/TK1/Linux_for_Tegra_tk1/bootloader I run:
sudo ./nvflash --read APP system.img --bl ardbeg/fastboot.bin --go
it prints out: Nvflash 4.13.0000 started
Then it hangs for 18 hours without anything seemingly changing in the directory.
Any idea?

Just tried a few times and it worked out.

One thing that could get in the way is that you cannot do two operations in a row on a recovery mode Jetson, e.g., you cannot clone the partition table and then clone the root partition without resetting the Jetson into recovery mode between operations. Perhaps recovery mode had something going on which needed to be reset.