Should I back up the XEN hypervisor?

Question

Backup

Good day!
I have formed 2 questions, the answers to which I could not get from open sources))
1. There is an opinion that it is better to install the hypervisor on a memory card or USB flash drive. I am familiar with the technology in principle and it seems to me that this is the right decision, but I would like to hear the opinion of a more experienced community. If your opinion is in solidarity with the opinion of Google, then tell us about the advantages and possibly disadvantages, and how fast media is needed.
2. Actually continuation of the first question. Is it necessary to make a backup of this media in order to quickly return the server to normal in case of a possible fall (it is stupid to ask a question and try to answer it, perhaps this will not happen)? If you need to make a backup - do it after each addition of a virtual machine? Or is all information stored on the moons?
I apologize in advance for possibly incorrect questions!
And thanks in advance for your replies!

Answer 1

1) The advantage is that the flash drive is small, and this frees up the disk in the system, the flash drive is easy to copy and change to another. There are two drawbacks, slow speed and a limited number of write read cycles.
2) If you want to quickly restore them, do it as often as you need, it's logical to do it just once a day.