What to do on disk fault?

[popovn]

My config : 1 SSD + 1 HDD

What i must to do if (when) my SSD will die?
How to change for another plugged SSD?
All my data will safe ? ( All data on SSD cache does exist on HDD?)

[rufus20145]

All my data will safe ? ( All data on SSD cache does exist on HDD?)

No. When using drive based on Storage Spaces with Simple resiliency, data from SSD cache is not mirrored on HDD. And with 1 SSD + 1 HDD you can do either Mirroring (but very limited in size by smallest drive capacity, most likely SSD) or Tiered (with no resiliency at all)

[rufus20145]

How to change for another plugged SSD?

Plug it in, go to Storage Spaces in Control Panel, add it to Pool and rebuild it. Some data will probably be lost.