Server died, have to recover data from a Linux Software RAID 1 drive.

Take the drive and connect it to another linux computer.  You won’t be able to mount it out of the box; if you try you’ll get an error that states mount: unknown filesystem type ‘linux_raid_member’.

install mdadm:

create a virtual md device with mdadm

now you can mount the RAID 1 device

If you run into a device is busy error, stop mdadm

then try again