While trying to update a table definition (change a field type from NVARCHAR(5) to NVARCHAR(8)) we caused a lock on the database. There were a large number of rows (>11,000,000) so we decided to kill the process and roll back the update.
During the rollback the status of the process was showing as 'sleeping' with a Wait Type of IO_COMPLETION or PAGEIOLATCH_EX.
How can I give the KILL/ROLLBACK process a higher priority and prevent it going to sleep?