As the message says "ESXI 5.5.0 Bootbank cannot be found at path '/bootbank' ", what it means is it is not able to find the boot files and so any changes to the configuration cannot be done.
It can be due to various reasons some of which I am listing below :
- a firmware update on hardware.
- bad USB / SD card.
- corrupt partition.
I would recommend you to find out the following details as first step, as knowing as much as possible about the problem will make it easier for you to find a solution.
- Configuration changes made to the ESXi host recently.
- Driver / firmware changes made to the ESXi host.
- Any other known changes made to the environment post which you have started seeing this issue.
- Is it just one host on which you are seeing this issue.
"Is the USB boot drive going (or gone) bad? Something else? If the system reboots, is it going to be able to start? "
The answer is simple, you will have to reboot the host to find that out.
- I would recommend having a spare SD card / USB for just in case scenarios.
- You can check for the health on the hardware monitoring tools side (I doubt it is going to be very informative).
- You can re-seat the USB and then try doing a reboot.
- If you have a spare server, you can try booting that with this USB (Just to confirm if the it is USB that is faulty).- Check for the driver firmware recipe suited for your hardware and then boot the ESXi.
- Check for the latest driver / firmware suitable as per your hardware vendor.
- Try the new USB and install ESXi on it without impacting the existing datastore.
Anyhow you should also be thinking about migrating to version 6.x soon as 5.5 is coming towards end of its life and you may not be able to have any support for it (KB 51491).
Hope this solves your problem.
