Customer shutdown the server why server was starting up. After this one server did not boot up from raid card 3108. Error in RAID card interface was like this: "all of the disks from your previous configuration are gone."
1) Checked the logs, to understand when the problem appeared.
2) Asked customer what was done before error in details.
3) Connected remotely, checked that raid card was correctly detected by iBMC and system.
4) Checked current raid configuration and disks availability.
5) Found that Raid card did not see any disks at all.
6) Asked customer to check all cables and disks in the server. Customer confirmed all cables were in their place, disks also.
7) We suspect maybe there is a fault on blackplane, and we have applied the new spare part for this customer.
8) After the backplane was replaced customer confirmed server booted up with no problem. Previous configuration was healthy, no data was lost.
Root cause was unproper local maintenance, as customer turned off server when it was starting up by ejecting power cables from it. So backplane was damaged.
If Raid card is visible in the system and did not see any disks connected we should at first check cables, disconnect and connect them as 1st step. If situation still same and raid controller does not see any disks connected we need send the customer backplane+2 disk cables for replacement.
In my situation after customer replaced just backplane raid controller saw all his old disks and old configuration, and server booted ok. So the problem was solved.
It is impossible to predict such customer behavior. Customer just should follow the operation manual and turn off equipment correct way. And do not pull cables while server is working.