How to back up whole HCI infrastructure, particularly (big) indexes to ensure consistency?
You don't backup indexes. You shard them (for load balancing and scalability) and replicate them (for availability and backup). A good Index is one that is (almost) always up to date. A bad index is one that isn't. Imagine what your index will look like if you restored one from a week ago? Or even a day ago? Would you have any idea what's missing and whether or not you can even get it back?
Thanks, question cam from the customer. I got the answer.
What is the preferred way to back the rest, taking into consideration it is deployed on physical machines.
The OS and Docker are the customer's responsibility -- nothing changes there.
As for HCI -- "System Configuration --> Packages --> Export"
And when you need to restore, guess what you use? :-)
Retrieving data ...