Master on primary IDE:
C: drive
Slave on primary IDE: none
Master on secondary IDE:
D: drive
Slave on secondary IDE: tape drive
In the con®guration above, you do not need to change the jumper on the tape drive, but you may need to change the jumper on the D: drive. Some hard disks have three possible jumper settings:
vmaster
vmaster with a slave attached
vslave
If you have one of these hard disks and it is currently a ªmaster with no slaveº and you are adding the tape drive as a ªslaveº, then you must change the jumpers on the hard disk from ªmasterº to ªmaster with a slave attachedº. The
C:drive does not contend with other devices. The D: drive does contend with the tape drive. If a tape operation is in progress, a ®le access to the D: drive must wait for the tape drive to complete a command before starting the ®le access. Any application waiting for the ®le access to complete cannot run during this time.
Alternatively, if a ®le access to the D: drive is in progress, the tape drive must wait for the ®le access to complete before a tape operation can begin. This may cause an underrun and the tape drive must stop, rewind a little, and start forward again, which impacts tape drive performance. The con®guration above may be best when you have two hard disks and you have no need to run the tape drive while other applications are actively accessing the D: drive. There is no contention between the C: and D: drive.
Con®guration 4
Master on primary IDE: none
Slave on primary IDE: none
Master on secondary IDE: tape drive
Slave on secondary IDE: none
The con®guration above assumes that all of your hard disks are SCSI instead of IDE. In this con®guration, you must con®gure the tape drive as the master (MA) by placing a jumper over vertical pins 5 and 6. There is no contention for the devices.
2.Refer to your store controller documentation to determine if your store controller supports the cable select (CS) feature. With the cable select feature there is a special cable and the placement of the devices on the cable connectors determines whether a device is master or slave if the devices are set to CS. Most store controllers do not use this cable feature.
Chapter 2. Tape Drive Installation 5
