During the second step of the power-up sequence, the tape drive will respond with BUSY status to all ACI commands except Get Drive Info and Get Error Info. The amount of time taken by this second step will vary widely depending on three factors:
•The presence or absence of a cartridge in the tape drive
•The position of the media if a cartridge is present
•The ability of the tape drive to access the cartridge memory if a cartridge is present
HP recommends that the automation controller polls using the Get Drive Status command to monitor the completion of the power-up sequence. When the tape drive returns GOOD status to a Get Drive Status command, it has completed the power-up sequence.
If operating with a tape drive that supports ACI V4.1 and higher, HP recommends that the automation controller synchronizes the tape drive’s time stamping clock to its own using the Set Time command once the tape drive has completed the power-up sequence.
In some circumstances when responding to the first Get Drive Info command, the tape drive will fill every byte in the Manufacturing Date Code and Serial Number fields with FFh. The tape drive behaves this way when it receives the Get Drive Info command during the second step of the power-up sequence because it cannot access the EEPROM that stores this information at that time. The automation controller may retrieve the correct value for these fields with a second Get Drive Info command sent after the power-up sequence completes.
Once the power-up sequence completes, the automation controller can configure the tape drive using the Set Drive Configuration command. Each time a Set Drive Configuration command is sent, it is recommended that a Get Drive Configuration command is sent to double-check that the drive is configured correctly.
It is recommended that the Get Buffer Size command is sent to drive as part of the power-up sequence to determine the maximum burst buffer size and maximum receive/transmit package buffer sizes.
If a baud rate other than the default is to be used, then it is recommended that this is set during the power-up sequence using the Set Baud Rate command.
Recommended load-unload configuration
The Set Drive Configuration command provides access to several features that alter the tape drive’s behavior when loading or unloading cartridges. These give a large amount of flexibility in designing an automation controller.
HP’s experience suggests that certain configurations result in significantly fewer difficulties when integrating the HP Ultrium tape drive.
HP recommends configuration with the Auto-Eject feature disabled. If Auto-Eject is enabled, the drive will eject a cartridge in a variety of cases not directly controlled by the automation controller. These include receiving a SCSI LOAD/UNLOAD command with the Load bit set to 0, various load failures (regardless of the method of instigating the load), completion of the image verification step when upgrading the tape drive’s micro-code using a firmware upgrade cartridge, and completion of a head-cleaning cycle when using a cleaning cartridge. These ejects can result in both the automation controller and the tape drive losing track of the location of the cartridge.
44 Supporting Ultrium features
HP restricted