HP Proliant DL380 Gen9 got wet during Hurricane Irma, 2 hard drive configured as RAID 1 (Mirrored) are still good. Already ordered replacement, identical specs with the old one, Can I just simply plug in the 2 hard drive to the identical server and will the new server just boot up with the old hard drives?
The RAID configuration information is stored on the hard drives.
I would recommend plugging the hard drives back in to the same ports as they were plugged in to. Lastly, before proceeding to boot make sure your BIOS is configured to use and boot the RAID adapter and go in to the RAID configuration utility and make sure it recognizes your RAID 1 volume.
You shouldn't have any trouble.
However, whatever you do, do not try to initialize a RAID array or proceed to do anything that might try to rebuild the array if for some reason you are not seeing a healthy RAID volume right away.
Does / did the wet server have a smart array or hba? Because that will affect what you need to do to put them into the new server.
Smart arrays in the pcie or LOM slot hold a raid Configuration for the disks where a hba would just pass through to the hard disks.