Please see the bottom of the
installation page.$this->bbcode_second_pass_quote('', 'P')lace your boot drive in another Linux computer/device and check the file system. If you're still having issues then we'll proceed with starting from scratch on the rootfs. Following steps 7 and 8 above, partition and format the drive (using the correct /dev device, highly likely NOT sda). Download and extract the root filesystem tarball onto the new ext3 partition as the root user, not just sudo. Create a file at /usr/local/mac_addr and place in it your Pro's MAC address (its on the bottom of the unit) in the format XX:XX:XX:XX:XX:XX. Safely umount the drive from the computer, plug it back in to the powered-off Pogoplug, and then plug in the Pogoplug.
If you have further questions I'll attempt to help but as I said in your other thread, starting fresh at this point is likely a lost cause with this hardware.