User manual QUANTUM 00220201

[. . . ] DLT VS160 SCSI Interface Guide DLT VS160 SCSI Interface Guide Copyright Copyright © 2003 by Quantum Corporation. Document Origination: Boulder, Colorado, USA. Trademarks Quantum, the Quantum logo, and the DLTtape logo are trademarks of Quantum Corporation registered in the U. S. A. DLTtape, DLTSage, Value DLTtape, and Super DLTtape are trademarks of Quantum Corporation. Other company and product names used in this document are trademarks, registered trademarks, or service marks of their respective owners. Legal Disclaimers The information contained in this document is the exclusive property of Quantum Corporation. [. . . ] The tape drive does not support this feature; this field must be set to 0. The tape drive does not support Extended Contingent Allegiance, so this bit must be set to 0. The tape drive does not support Asynchronous Event Notification (AEN). The tape drive does not support Asynchronous Event Notification. The tape drive does not support Asynchronous Event Notification. The tape drive does not support Asynchronous Event Notification. The tape drive does not support this feature; this field must be set to 0. The tape drive does not support this feature; this field must be set to 0. 4-68 December 2003 002202-01 DLT VS160 SCSI Interface Guide Chapter 4: SCSI Commands 4. 9. 6 Data Compression Page (0Fh) The Data Compression Page specifies parameters that control data compression. This page allows the user to enable or disable the tape drive's compressed format independently of the tape's position. Additionally, it allows the user to enable or disable decompression of the tape drive's compressed data during write operations. Note: In this page, you can only change the DCE bit. Bit Byte 0 1 2 3 DCE DDE (MSB) 4-7 Compression Algorithm (LSB) (MSB) 8 - 11 Decompression Algorithm (LSB) 12 - 15 Reserved DCC RED 7 Reserved 6 5 4 3 2 1 0 Page Code (0Fh) Page Length (0Eh) Reserved Reserved Figure 4-44. Data Compression MODE SELECT Page -- Data Format Table 4-38. Field Name DCE Data Compression MODE SELECT Page -- Field Descriptions Description Data Compression Enable. The Data Compression Enable bit specifies whether the tape drive should enable or disable data compression. When DCE is set to 1, the tape drive starts in compressed format. The DCC bit is used by the MODE SENSE command to indicate that the tape drive supports hardware data compression. When the tape drive reads compressed data from tape, it automatically decompresses the data before sending it to the initiator. Data decompression/compression is always enabled, so this bit must be set to 1 (enable data decompression). DCC DDE 002202-01 December 2003 4-69 Chapter 4: SCSI Commands DLT VS160 SCSI Interface Guide Table 4-38. Field Name RED Data Compression MODE SELECT Page -- Field Descriptions (Continued) Description Report Exception on Decompression. The tape drive does not report exceptions on decompression (boundaries between compressed and uncompressed data). The Compression Algorithm field indicates which compression algorithm the tape drive uses to process data from the initiator when the DCE bit is set to 1. Specifying a value other than 10h for this field causes the tape drive to return CHECK CONDITION status with the Sense Key set to ILLEGAL REQUEST. The Decompression Algorithm field indicates which decompression algorithm the tape drive uses when decompressing data encountered on the tape. Specifying a value other than 10h for this field causes the tape drive to return CHECK CONDITION status with the Sense Key set to ILLEGAL REQUEST. Compression Algorithm Decompression Algorithm 4-70 December 2003 002202-01 DLT VS160 SCSI Interface Guide Chapter 4: SCSI Commands 4. 9. 7 Device Configuration Page (10h) The tape drive supports the Device Configuration page, which has the following format. Bit Byte 0 1 2 3 4 5 (MSB) 6-7 Write Delay Time (LSB) 8 9 10 (MSB) 11 - 13 Buffer Size at Early Warning (Optional) (LSB) 14 15 Select Data Compression Algorithm Reserved EOD Defined DBR BIS RSmk AVC Gap Size EEG SEW Reserved SOCF RBO REW Rsv'd CAP CAF Active Partition Write Buffer Full Ratio Read Buffer Empty Ratio 7 PS (0) 6 0 5 4 3 2 1 0 Page Code (10h) Additional Page Length (0Eh) Active Format Figure 4-45. [. . . ] Data Transfer Descriptor -- Data Format 5-26 December 2003 002202-01 Chapter 5: Medium Changer Device Commands DLT VS160 SCSI Interface Guide Table 5-17. Field Name Data Transfer Descriptor -- Field Descriptions Description This field indicates the address of the medium changer element whose status is reported by this descriptor block. This value is always 1, indicating that access to the element by a medium transport element is allowed. An exception bit of 0 indicates the element is in a normal state. If this bit is 1, information on the abnormal state may be available in the Additional Sense Code and Additional Sense Code Qualifier fields. [. . . ]