IN-OPERATION TEST SYSTEM FOR MAGNETIC DISK

PURPOSE:To realize execution of the test of a magnetic disk medium during its operation without discontinuing the use of a magnetic disk via a user program by making the user program to perform the input/output operations during the test of the magnetic disk device with no consciousness of this test. CONSTITUTION:The medium of a magnetic disk 1 is carried out for each medi um test part 1a of a track group. At the same time, the information on a spe cific present range of tracks where the media of disks 1 are to be tested is stored in a medium test part information memory table 6. Then an input/output request holding means 4 holds only the user program to be sent into and taken out of said range and permits the input/output of the user program to other tracks where no medium test is carried out at present. When an access is going to be given to a range of the track having a medium test, the input/output request held by the means 4 is released by a release means 7 after the test of the medium in the relevant track range. Thus it is not required for the user program to stop the use of the disk 1 and the test is possible for the medium of the disk 1 during its operation.