When server start, the raid controller report "There are offline or missing virtural drives with preserved cache" ,it is impossible to enter the Operating System.
1, According to the error message, in this raid controller, there was disk failure or missing, and the cache data was impacted.
2, In this situation , it is impossible to enter OS before discard the cache.
3, The method to discard cache is different in different raid controller, for example, in SAS raid 2208, we can discard cache in below screen.
4, In 3108 raid controller, Press F2, select "Manage Preserved Cache" in below screen:
5, Press "Tab" and move the cursor on "DISCARD CACHE", and press "enter"
6, Click "Yes" to discard cache and then reboot the server.
1, This issue could happen on all servers, different raid controller.
2, If there is very important data in the cache, please don't discard cache and contact technical team to recover data.