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HP LTO Ultrium 6 Tape Drives Technical Reference Manual Volume 2: Software Inte

HP LTO Ultrium 6 Tape Drives Technical Reference Manual Volume 2: Software Integration Abstract This is one of five volumes that document HP LTO Ultrium 6 tape drives (Fibre Channel and SAS). This volume provides software integration information. See “Support and other resources” (page 67) for details of the other guides. HP Part Number: n/a Published: October 201 2 Edition: First © Copyright 201 2 Hewlett-Packard Development Company, L.P. The information contained herein is subject to change without notice. The only warranties for HP products and services are set forth in the express warranty statements accompanying such products and services. Nothing herein should be construed as constituting an additional warranty. HP shall not be liable for technical or editorial errors or omissions contained herein. Acknowledgements Windows is a U.S. registered trademarks of Microsoft Corporation. UNIX is a registered trademark of The Open Group. Warranty WARRANTY STATEMENT: To obtain a copy of the warranty for this product, see the warranty information website: http://www.hp.com/go/storagewarranty Contents 1 Designing backup applications....................................................................7 Optimizing performance...........................................................................................................7 Large data transfer size.........................................................................................................7 Data compression control......................................................................................................7 Non-immediate commands...................................................................................................7 Managing the use of tapes........................................................................................................8 Information in Cartridge Memory...........................................................................................8 Cleaning tape heads............................................................................................................8 Monitoring tape use.............................................................................................................8 TapeAlert............................................................................................................................8 Diagnostic logs....................................................................................................................8 Displaying drive information..................................................................................................9 Drive tests...........................................................................................................................9 Design goals for LTO backup applications....................................................................................9 2 Configuration and initialization..................................................................10 Operating system drivers.........................................................................................................10 Inquiry string recovery........................................................................................................10 Example......................................................................................................................11 Support for additional LUN......................................................................................................11 Enabling additional LUN support.........................................................................................11 Supporting additional LUNs................................................................................................12 3 Use of tapes............................................................................................13 LTO cartridge memory.............................................................................................................13 Identifying tape cartridge types................................................................................................13 Using Cartridge Memory attributes.......................................................................................13 Using MODE SENSE..........................................................................................................13 Tape status and capacity.........................................................................................................13 Finding the remaining capacity............................................................................................14 Interpreting Log Sense data.................................................................................................14 Using the SET CAPACITY command.....................................................................................14 Command descriptor block.............................................................................................15 CDB fields....................................................................................................................15 WORM media.......................................................................................................................15 How WORM media works..................................................................................................15 Changes to SCSI commands...............................................................................................16 New commands...........................................................................................................16 New INQUIRY pages....................................................................................................16 New log pages.............................................................................................................16 New parameters in the DTD Status log page................................................................16 New and changed mode subpages.................................................................................17 New additional sense codes...........................................................................................17 New task management functions.....................................................................................17 Re-writing media labels......................................................................................................17 Allow overwrite of last filemarks before the EOD data set........................................................17 Using CM to check tape integrity.........................................................................................17 Behavior with a missing or inconsistent EOD value.................................................................18 Unique media identifier......................................................................................................18 Barcode support................................................................................................................18 Responding to Cartridge Memory data......................................................................................18 Load count .......................................................................................................................19 Contents 3 RWW retry counts.............................................................................................................19 Corrective action...........................................................................................................19 4 Factors affecting performance....................................................................20 Ways of optimizing performance..............................................................................................20 Detecting the drive’s speed..................................................................................................20 Ensuring the recommended minimum transfer sizes.................................................................20 Maximum block size......................................................................................................21 Media type identification....................................................................................................21 Using Cartridge Memory instead of tape headers..................................................................21 Using the Performance Log page for diagnosing problems......................................................21 Time-out values.......................................................................................................................21 Notes:..............................................................................................................................21 Recommended support of log pages.........................................................................................22 Factors affecting performance..................................................................................................22 Host-related factors............................................................................................................22 Drive-related factors...........................................................................................................23 Format-related factors.........................................................................................................24 5 Supporting Ultrium features........................................................................25 Cartridge Memory (LTO-CM)....................................................................................................25 Further information.............................................................................................................25 Automation interface...............................................................................................................25 Automation/Device Interface (ADI).......................................................................................25 Automation Control Interface (ACI).......................................................................................26 Modes of usage through ACI..........................................................................................27 Slave to a library controller........................................................................................27 SCSI pass-through mode............................................................................................27 ACI command set..............................................................................................................27 ACI commands that affect drive streaming performance..........................................................27 New features in ACI 4.4.....................................................................................................28 Backward compatibility..................................................................................................28 Encryption support........................................................................................................30 Further details....................................................................................................................31 Supporting the ACI protocol................................................................................................31 Recommended ACI time-out values.......................................................................................31 Treatment of reserved fields.................................................................................................32 Recommended power-up sequence.......................................................................................32 Recommended load-unload configuration..............................................................................33 Recommended Get Drive Status polling frequency..................................................................33 ACI protocol communications retry.......................................................................................33 Upgrading the drive firmware..............................................................................................33 Firmware upgrade via tape.............................................................................................33 Firmware upgrade via the primary host interface...............................................................34 Firmware upgrade via ACI..............................................................................................34 Library firmware upgrade via tape...................................................................................34 Reporting of cartridge types................................................................................................35 ACI 4.3 and earlier.......................................................................................................35 ACI 4.4 mode..............................................................................................................35 Handling irregular cartridges..............................................................................................36 Cleaning cartridge (HP-configured or Universal)................................................................36 Expired cleaning cartridge (HP-configured or Universal).....................................................36 Non-HP Ultrium 1 cleaning cartridge...............................................................................36 Unreadable data cartridge.............................................................................................36 Ultrium 7 and later data cartridges..................................................................................36 Data cartridge with unreadable CM................................................................................37 4 Contents Cartridge fails to seat or load.........................................................................................37 Cartridge cannot be loaded...........................................................................................37 Valid firmware upgrade cartridge....................................................................................37 Invalid firmware upgrade cartridge..................................................................................37 Frequently asked questions..................................................................................................38 Cleaning..........................................................................................................................38 Resetting drives..................................................................................................................38 Resetting via the ACI Reset command...............................................................................38 Resetting using the ACI_RST_L line...................................................................................39 Further details....................................................................................................................39 Backup software.....................................................................................................................39 Controlling data compression...................................................................................................39 Other mode page information..................................................................................................39 Accessing Cartridge Memory without threading the tape........................................................39 Buffer size at EW-EOM.......................................................................................................40 Synchronize at EW-EOM.....................................................................................................40 Write delay time................................................................................................................40 Rewind on reset.................................................................................................................40 Partition size......................................................................................................................40 6 Sense keys and codes...............................................................................41 Sense keys—actions to take.....................................................................................................41 Additional sense codes—actions to take....................................................................................43 0h—NO SENSE................................................................................................................44 1h—RECOVERED ERROR....................................................................................................44 2h—NOT READY...............................................................................................................45 3h—MEDIUM ERROR.........................................................................................................46 4h—HW ERROR...............................................................................................................49 5h—ILLEGAL REQUEST.......................................................................................................50 6h—UNIT ATTENTION.......................................................................................................51 7h—DATA PROTECTION....................................................................................................53 8h—BLANK CHECK..........................................................................................................55 Bh—ABORTED COMMAND...............................................................................................55 Dh—VOLUME OVERFLOW.................................................................................................56 7 Exception handling...................................................................................57 Typical escalation procedure....................................................................................................57 Monitoring the condition of the drive and media.........................................................................57 Supporting TapeAlert.........................................................................................................58 Flags...........................................................................................................................58 Designing software to use the TapeAlert log...............................................................................63 TapeAlert Models..............................................................................................................63 TapeAlert polling usage model.......................................................................................63 TapeAlert informational exception usage model................................................................64 Reading the TapeAlert log...................................................................................................64 One-Button Disaster Recovery (OBDR).......................................................................................65 Supporting OBDR..............................................................................................................65 Responding to the ‘Clean’ LED.................................................................................................65 Providing pass-through mode...................................................................................................65 Requirements for drivers and logical device managers............................................................65 8 Support and other resources......................................................................67 Related documents..................................................................................................................67 Documents specific to HP LTO Ultrium drives..........................................................................67 Documentation map...........................................................................................................67 Drives—general............................................................................................................67 Contents 5 Installation and configuration..........................................................................................67 Operation....................................................................................................................67 Cartridges....................................................................................................................68 Interface......................................................................................................................68 Maintenance and troubleshooting...................................................................................68 Dealing with errors........................................................................................................68 LTO Ultrium features.......................................................................................................68 General documents and standardization...............................................................................69 Glossary....................................................................................................70 Index.........................................................................................................71 6 Contents 1 Designing backup applications In today’s computer market, software applications that use tape drives to copy the information from a computer’s hard disk for safe keeping are readily available for many different operating systems. Unfortunately, not all these applications take advantage of the advances made in tape technology over the past few years. This section examines some of the characteristics that a good backup utility should include. Optimizing performance There are some fundamental things that tape management applications should implement when dealing with Ultrium drives: • Use large data transfer sizes. • Control and monitor data compression. • Ensure directory information is safe and accurate. • Maximize the use of the tape drive’s internal buffering capability. Each of these is discussed below. For more information on optimizing performance, see “Factors affecting performance” (page 20). Large data transfer size Applications should use large data transfer sizes to make better use of the Ultrium drive’s internal buffers. A good goal to set is at least 256 KB each for read or write operation, with an ideal target of 5 1 2 KB: • For fixed-length block mode reads and writes, provided the block size multiplied by the number of blocks to be transferred is at least 256 KB, drives will provide peak performance. Small block sizes (5 1 2 bytes) are acceptable so long as they are written and read in fixed-length block mode using large transfers. • For variable-length block mode reads and writes, the transfer length should be at least 256 KB. For FC drives, it is possible to read Report Port Speed Capabilities information and report if a drive is connected via a sub-optimal interface. For SAS drives, you can use the Protocol Specific Port log to evaluate if the attach speed is sub-optimal. Data compression control Ultrium drives have built-in hardware data compression. Backup applications should incorporate features to report the actual compression ratio achieved during backup operations. The typical compression ratio achieved during backup operations on PC and UNIX networks is 2: 1 , but this can vary widely depending on the actual data being compressed. For more information, see “Controlling data compression” (page 39). Non-immediate commands Performance can be improved by only using immediate mode WRITE FILEMARKS commands. NOTE: Using immediate mode with other commands does not improve performance and can cause problems when writing a driver. The SCSI specification requires that if a command is issued with the IMMEDIATE bit set to 0, the drive must flush its data buffer before it carries out the operation. This takes time. Optimizing performance 7 Managing the use of tapes The Ultrium format enables applications to monitor the performance of tapes closely, to indicate when tape heads need cleaning, and when a tape should be discarded. See “Use of tapes” (page 13) for more information. Information in Cartridge Memory The LTO Cartridge Memory holds a number of pages of information that contain data about the tape’s history, such as the amount of data written to and read from the tape, the number of times a cartridge has been loaded and the tape threaded into a drive, and the number of read or write errors that have been encountered by drives with this tape. This information can be used to warn against backing up onto a tape of dubious quality, or one that is reaching the end of its life. Cleaning tape heads The ‘Clean’ LED on the front of HP Ultrium drives indicates when a cleaning cartridge should be used. There are two ways for backup applications to determine when the tape heads need cleaning and to prompt the user to clean the drive: • Use TapeAlert—see “Monitoring the condition of the drive and media” (page 57) for details. • Send a SCSI REQUEST SENSE command to look at the CLN bit in the sense data. If the bit is set, the drive needs cleaning. Monitoring tape use Drives can report the actual amount of data that has been written to the tape, and the amount of available space on the tape. From this information, applications for Ultrium drives can be designed to calculate the percentage of tape used, and give the user feedback on the actual progress of the backup operation. This is a significant improvement over other technologies, such as DC6000 QIC products, that require the application to estimate what is going on. See “Tape Capacity Log Page” under uploads/Management/ sop-guide 2 .pdf