disktest Test Modes

Connection 

Yes 

Only one instance of disktest (which monitors UNIX error messages) is allowed for each disk device. disktest displays messages and reports errors. The test also opens the hard disk, checks the disk configuration, reads a few blocks, and then closes the hard disk. No File System subtest is run. No Write option is available in Connection test.

Functional 

(Offline) 

Yes 

More than one instance of disktest is allowed for one disk device. The File System subtest, Media subtests, and floppy test can be run in offline Functional test mode.