How to safely recover from this mega failure ?

Hi,
my OMV installation WAS 3.0.7x. It was not remotely answering from a couple of weeks and I could not phisically access it until this evening.
It is a 2 parts hardware setup: one part is an HP316M1 with IBM1015 controller on it, the other part a case with 24 3,5" bays and HP sas expander, apower supply and a PCI module to power to the HP expander.
Two raid groups were on it:
14x3TB drives
6x4TB drives
RAID6 both !

Switching the NAS on a smell of burned electronic raised from the HP316M1 and soon it switched off.
From the 24 Bays case a continuos clicking was coming up from one or two drives.

Ok, you are right, it is an horror story.

Now I need to try to rebuild and recovery everything.

I need some advice from the experts:

Once I move the IBM card to another PC and connect it back to the 24Bays case, I need to discover what happened to the drives and eventually which have failed and recover sanity before trying to reinstall OMV. I need to do this in the safe possible way.

Which tools do I need ? Which shell commands ? Which distribution/iso ?
Any warning ? It is really an huge setup and I want to recover everything or as much as possible.
Also I don't want any tool to start rebuilding the drives automatically but only if I manually start the process.

Any help is highly appreciated !

Without any answer I don't want to make any action on the dead corpse !

Update:

I have moved the system drives and the IBM 1015 controller to another HP Gx machine. There was an ESXi Hypervisor installed. I have created a virtual machine and passed the system drives as RAW and the controller as passthrough device...
... everything was there, even the spare drive for each of the 2 RAID6.
Openmediavault worked at first run after omv-firstaid network configuration.

Thanks god !