MSA max. LUN ID is 1023.
https://support.hpe.com/hpsc/doc/public/display?docId=emr_na-c05075467
For more Information look in:
https://support.hpe.com/hpsc/doc/public/display?docId=c00403562
But XENSERVER i did no know.
Why you use so high LUN ID?
Ins't 1- 254 good?