HWT003 How to use SCSI tape drives with MVS3.8j and Hercules
Using a SCSI tape drive with MVS3.8j and Hercules is relatively painless. There are only two options used in the hercules.cnf that need to be considered. The first is the --no-erg option that indicates the drive cannot execute the erase gap command. You may have to check the drives documentation to see if this option needs to be used. The other option is --blkid-32 and --blkid-22(default). This option indicates the number of bits reported when a request is made for the tape position. The device type to use for non-IBM mainframe drives is 3420 (emulates a reel to reel drive) or 3480 (emulates a catridge drive). The host OS device name is usually "/dev/nst0" for Linux or "\\.\Tape0" for Windows. An important note when using IEHINITT to initailize a tape is it takes care not to destroy an inadvertantly mounted production tape by refusing to initialize a tape that is already mounted when the job starts. To get around this you must use in the hercules.cnf file a definition that indicates the drive is empty (example: "0480 9348 *" instead of "0480 9348 /dev/nst0". You could also enter "DEVINIT 480 *" on the Hercules command line before submitting the job and skip changing the .cnf file.). You will get a MVS console message requesting the device name of the drive to be used. Enter on the Hercules command line "DEVINIT 480 /dev/nst0" and follow it with an MVS reply "r msgid,480". Message IEC701A will then be issued to confirm you want to init the tape and the correct response is "r msgid,m". Please Help Improve This Page by emailing me a comment on any options you found you needed to use for a particular drive below. IBM 9348: Use device type 9348 in the .cnf file, no --blkid option is needed.