There are three adapters in this output that are generating the same error message - mpx.vmhba2:C0:T0:L0, mpx.vmhba2:C3:T0:L0 and mpx.vmhba36:C0:T0:L0.
The translated error message is: illegal request - invalid command operation code. This means the devices do not support the command they are receiving.
Do you know what device each of these adapters relates to? Using the vSphere Client go to Host -> Configuration -> Storage Adapters and figure it out (select each device and look at the Name, Runtime Name and Type columns). They could simply be harmless messages generated for devices that you don't need to worry about - for instance the CD-ROM drive or the raid enclosure (not the disks themselves), etc.
Hi nirvy,
thank you for your quick response! I checked the three devices:
mpx.vmhba2:C0:T0:L0 is the local adaptec disk (RAID 1 SSD, I suppose it shows only as one disk)
mpx.vmhba2:C3:T0:L0 is the enclosure of the RAID Adapter, in my world this would be some sort of physical case of some sort. No Idea why this needs to be addressed with SCSI commands at all 
mpx.vmhba36:C0:T0:L0 is a CDROM attached to the local SATA controller.
What bothers me is the first one, which is not from the "harmless message generated by need not worry device" category but rather the disk I want to use to run ESXi of and use as buffer, because it should run like a cheetah on those Intel SSD. So what do I do?
Cheers
Fritze