Initializing the DASD with the DIAG discipline failed. Possible reasons for
this problem are that the device has a device type other than FBA or ECKD,
or has a block size other than one of the supported sizes:
512 byte, 1024 byte, 2048 byte, or 4096 byte.
User response
Ensure that the device can be written to and has a supported device type
and block size. For details about the return code see the section about
the INITIALIZE function for DIAGNOSE Code X'250' in "z/VM CP Programming
Services". If you cannot resolve the error, note the error code and contact
your support organization.