You need a USB memory stick (or SD card) with at least 4 GB of memory to create a Chromebook recovery image (Figure B).
Figure B
Create a Chrome OS recovery image with any USB memory stick with 4 GB (or more) of storage.
Here's how to create a USB recovery image:
When ready, enter the following in Chrome's omnibox (where you normally type URLs):
chrome://imageburner
Insert your USB memory stick. The system will detect it and then notify you that all files on the memory stick will be erased. Select OK to continue (Figure C).
Wait several minutes. You'll see a series of prompts as the system downloads, extracts, and copies the recovery image.
Remove the stick when prompted.
You now have a USB memory stick with a recovery image for your Chromebook.
Figure C
Wait for the system to download, extract, and copy the recovery image.
Recovery images are unique to each Chromebook make and model. A recovery image made for one HP Chromebook 11 will work on another HP Chromebook 11, but not on a Dell Chromebook 11. You should make at least one recovery image for each make and model of Chromebook you manage. Label -- or otherwise identify -- your USB memory sticks by system.