Under heavy load the Debian Kernel 4.14-13 crashes on high memory load and let the CPU freeze. Not really funny so rollback to older version
Warning: If you setup a Server with LVM and Software Raid 1 – 5 and a Crash happens the LVM blocks the saving of the EXT-3 File Journal to the HDD.
Solution: Do not use LVM with Software RAID !!! to keep DATA save. Same with Luks Encryption and LVM!!!