ReadyNAS RN102 Doesn't want to update

The update from 6.2.5 to 6.4.0+ on ARM systems such as the RN102 involves a u-boot update however the u-boot update doesn't happen doing the update normally leading to the system failing to boot.

The way to update from pre-6.4.0 firmware to 6.4.0 (or newer) is following the following guide: ReadyNAS OS 6: RN100/RN2120 cannot update due to invalid checksum 

Once you are on 6.4.0+ you can update as normal from then on.

For USB Boot Recovery the USB key needs to have the initrd-recovery.gz, uImage-recovery and the firmware image on it. Note when you download the firmware you get a zip file. You need to extract the contents of that and put the .img file onto the USB key.

Not all USB keys are compatible so you could have to try multiple ones before finding one that works.

Note that booting off USB is not accessing the boot menu. Booting off USB doesn't involve pressing the reset button at all on the RN102, but rather pressing the Backup button on the front of the NAS with your finger.

1. Power down your ReadyNAS storage system.
2. Insert the prepared USB drive into the front USB port.
3. Press and hold the Backup button, then power on the ReadyNAS system and continue to hold the Backup button for up to 15 seconds, depending on your ReadyNAS model (you might not know when the unit is entering USB Recovery mode unless your USB drive has an activity indicator. If your USB drive does not have an activity indicator, hold the Backup button for a full 30 seconds to ensure that your ReadyNAS system is in USB Recovery mode).
4. Wait for the ReadyNAS system to finish with the recovery and power down.
5. After the system powers down, remove the USB drive and try booting normally.

If you try to boot off a USB Boot Recovery key with no firmware image on it then it should get into an error state where you can ping it and get a login prompt if you telnet to the NAS I.P. address on the default telnet port 23. Note the I.P. address will be picked up via DHCP.