Troubleshooting Aid: Libraries/Autoloaders/DLT Drives

Introduction

The Libraries, Autoloaders and DLT drives in this `Troubleshooting Aid' documentation are all for SCSI-2 interface and the Quantum DLT drives. This is a general `Troubleshooting Aid' and problems may vary from system to system. This `Troubleshooting Aid' was developed by `Network (Removable) Storage Engineering' in order to aid the field support team to better support and service our Sun clients. This is not intended to be a complete `Troubleshooting Aid' for all aspects of field issues, but rather this can be a good starting or reference point to review the latest information available in troubleshooting aids before visiting a customer for a service call. This `Troubleshooting Aid' will be up dated as better techniques in troubleshooting become available and when new firmware (f/w) or new patches are released. The goal we wish to accomplish with this document is as follows: The customer is up and running in the shortest possible time and no frustration has set in to any party...

Table of Contents

• 1.0 Troubleshooting Wisdom
• 1.1 General Things to Check First
• 2.0 SCSI Terminators
• 2.1 Single-ended SCSI Terminators
• 2.2 Differential SCSI Terminators
• 3.0 Firmware History for DLT Drives/Matrix: 2/15/00
• 3.1 DLT4000 Firmware History Matrix
• 3.2 DLT7000 Firmware History Matrix
• 3.3 DLT8000 Firmware History Matrix
• 3.4 How to Read the Firmware on a DLT Drive
• 3.5 Commands Available to Find the Firmware Revision of a DLT Drive
• 4.0 Firmware Change Descriptions
• 5.0 Firmware History for Robotics, Library/Autoloaders Matrix: 2/15/00
• 5.1 L11000 Library Robotics Firmware History Matrix
• 5.2 L3500 Library Robotics Firmware History Matrix
• 5.3 L1800 Library Robotics Firmware History Matrix
• 5.4 L1000 Library Robotics Firmware History Matrix
• 5.5 L280 Autoloader Robotics Firmware History Matrix
• 5.6 L9 Autoloader Robotics Firmware History Matrix
• 6.0 Personality Bits for DLT Drives (EEPROM values, page 3Eh)
• 7.0 Density Codes and Data Compression - What is the Difference ?
• 7.1 Density Code Selection
• 7.2 Data Compression
• 7.3 Two Types of Data Compression
• 7.4 Selecting Density and Capacity Gains
• 7.5 Density Code Selection Parameters (from UNIX and drive level, DLT7000)
• 7.6 Cartridge Tape Specifications
• 7.7 Media and Drive Compatibility
• 8.0 Performance Issues
• 8.1 Things to Check When Performance Seems to Suffer
• 8.2 If the Performance has Degraded After Some Length of Time, Check the Following
• 8.3 Setting SCSI Options Parameters (/etc/system file)
• 9.0 /kernel/drv/st.conf Issues
• 9.1 Explanation of the "tape-config-list" Section of the st.conf File
• 9.2 How to Initially Set Up the /kernel/drv/st.conf Parameters
• 9.3 Explanation of Parameters for the st.conf File
• 10.0 Windows NT and DLT Drives
• 11.0 Independent Software Vendors (ISV)/Backup Utilities Matrix
• 12.0 Tape Cartridge Handling and Car
• 12.1 Quick Cartridge Inspection - What to Look for
• 12.2 Drop Leader Issues with DLT Drives
• 13.0 Utilities (Software)
• 14.0 Patches & BugIDs - Matrix for Libraries and Autoloaders ONLY
• 14.1 L11000
• 14.2 L3500
• 14.3 L1800
• 14.4 L1000
• 14.5 L400/DLT4700
• 14.6 L280
• 14.7 L9
• 14.8 L20
• 15.0 Patches & BugIDs - Matrix for Libraries & Autoloaders, DLT Drives ONLY
• 16.0 DLT Drive Serial and Model Number Format Definitions
• 16.1 Serial Number Format
• 16.2 Model Number Format
• 17.0 Error Codes
• 17.1 Drive Level Internal Error Codes
• 17.2 SCSI, System Level Status Codes

Troubleshooting Wisdom

• Always break the problem down to its simplest form and fix the simple problems first.
• Never try to tackle all issues at once, because confusion can set in easily.
• Never proceed further before fully resolving the simple issues discovered first.
• Understand the issue clearly first. Listen to the customer clearly and note all points, even the seemingly insignificant ones.
• Be very informed about the product technically. This Troubleshooting Aid will help achieve that.

General Things to Check First

Here are some of the basic things to look at first in the Troubleshooting of Libraries and Autoloaders with SCSI DLT drives. Ensure you have good SCSI cable connections and visually check the pins and the thumb screws. For perpetual or unexplained errors, repeated power supply or drive failures, confirm the A.C. line is clean, meets specification and is noise free. If necessary, connect an AC line analyzer for the duration of backing up data and confirm there is a good AC supply by monitoring this line for two to three days. Check AC connectors and for good grounding. Here are some inexpensive AC line monitors can be purchased and used at a depot level. Remember, these AC line monitors will help recognize the first sign that problems may exist with the AC line. For a more detailed analysis, obtain an AC line monitor that has a print out and full capabilities. It may also be necessary to call the AC power supply manufacturer. It is also a good idea, when in doubt, to monitor the site for a clean AC line for three days or so when a new installation is planned.

This document cannot go into AC line specification in detail. For such details, please inquire with the AC power supply manufacturer. Since this document will be available world wide, listed below are some inexpensive monitors for countries that may have difficulty in obtaining such monitors. Please note, these are only suggestions.

• Tasco Inc, Model: ACM120 120/220/230/240 volts (specify needs when ordering)
• Warns of possible damage from unstable power source
• Monitors voltage supplied to the equipment
• Verifies the lines ability to handle needs
• Indicates spikes, high voltage, low voltage, power failures or brown outs.
• Tasco Inc: Model: CPM 200 120/220/230/240 volts (specify needs when ordering)
• Measures true RMS voltage supplied to the computer
• Warns of power problems that can cause computer malfunction
• Displays the recommended solution to correct any power problems indicated

	Tasco Inc.
      	2895 West Oxford Avenue, #7
	Englewood, Colorado, 80110, U.S.A.
	Tel: 1-800-999-9952 (In the USA)
	303-762-9952 (Outside of the USA)
	303-762-1205 FAX                                                                                                

http://www.tasco-usa.com/

SCSI Terminators

SCSI terminators are very important. There are generally two types for SCSI use.

• Single-ended terminators
• Differential SCSI terminators

Single-ended SCSI Terminators (SE)

Part number 150-2267-01 for wide (16 bits) SCSI are used for SCSI devices that support single-ended interfaces. On Sun external terminators, look on the case of the terminator, there should be a symbol which indicates it is an SE terminator.

Devices can be placed up to 6 meters from the host and only the last device needs to be terminated, if the last device is not an auto-terminating device.

Depending on the speed of the transfer rate, use the following pointers:

• The SCSI length limits are based on the speed of the fastest device attached to the bus.

* - 1.5 meter limit for 4 or less devices, 3 meters for more than 4 devices.

Note:Only SE terminators can be used for single-end SCSI bus/devices.

Differential SCSI Terminators (HVD = high voltage differential)

Part number 150-1890-02 HVD terminators are used for SCSI devices that support the differential SCSI interface. All of Sun's libraries are HVD. For Sun external terminators, look on the case of the terminator, there should be a symbol which indicates that it is a differential terminator.

Devices can be placed up to 25 meters from the host and only the last device needs to be terminated if the last device is not an auto-terminating device. For other makes of terminators see designation on the terminator case itself. It is rare, but terminators can also go bad. In some intermittent and unexplained problems, do go ahead and replace the terminator and test. Also make sure the term power at the terminator meets specification of 5v +/- 5% in most cases and noise does not exceed, best case, 50v p/p.

Note 1: If an SE terminator is used on a differential bus, the bus will fail and no drives will be visible to the host. The same happens if a differential terminator is used on a single-ended SCSI bus.

Note 2: When external terminators have a green LED between the two thumb screws, when ON, indicates that the terminator is alive and is receiving +5v from the host adapter. Good first sign.

Firmware History for DLT Drives/Matrix:

Sun is currently using a few drive models, either in desktop, autoloaders or library configurations. These are the DLT4000 & DLT7000, DLT8000, DLT-1, SDLT and LTO.

• DLT4000 or DLT7000 for desktop & autoloader DLT4700
• DLT7000 for desktop & L280, L1000, L1800, L3500, L11000 Libraries
• DLT-1 from Benchmark
• SDLT (Quantum's, Super Digital Leaner Tape), Libraries
• LTO (HP&Seagate, Leaner Tape Open), Libraries

For the L1000, L1800, L3500 and L11000, the DLT7000 drive firmware is the same, but the L280 has different drive firmware revision. Remember the drives communicate with the library controllers via a serial port internally and hence different manufacturers implement their commands/timing slightly differently. So the drives talks to the library controller via serial port internally while it talks directly to the systems host adapter via SCSI protocol. Also don't forget the library talks to the system host adapter via SCSI protocol. Also Sun desktop DLT drives have different drive firmware than library drive firmware, as you can see below.

Note: Sun desktop DLT4000 and the DLT4700 autoloader drive, use the same firmware for the drives, xxsunxx. In general, when the firmware revision is indicated as `xxsun.xx', this is for Sun desktop DLT drives only and can not be used for library drives. If, on the other hand, the firmware revision is indicated as xxoml.xx (original manufacturing library), then the firmware can be downloaded to the DLT drive, and the drive would be one in an autoloader or Library, not a stand-alone drive.

Firmware History and Remarks:

Legend:

• OML = original manufacturing library
• OEM = original equipment manufacturing
• active = current recommended firmware revision
• discnt = discontinued, firmware no longer recommended
• generic = common for any system, as recommended by Quantum
• Inprocess = firmware under test, field can request this firmware if they have lab units to test for certain known issues

107590-01 obsoleted,
108094-01 obsoleted                                                                                                                                                                                                

To configure the st.conf file for the DLT8000 drive or the L-9 with DLT8000, use the following patches for Solaris S7 and S8.

Solaris 8: patch# 108725-03

Solaris 7: patch# 107460-10

Note: No st.conf modification is required for the DLT8000 drive once the above patch has been installed.

Supported on Solaris 2.5.1 and 2.6: Modify the st.conf file to include:

QUANTUM DLT8000 , Quantum DLT8000 , DLT8k-data ,

DLT8k-data = 1,0x36,0,0x9639,4,0x84,0x85,0x88,0x89,3;

For st.conf modification process, see section 9.0 below.

How to Read the Firmware on a DLT Drive

        TAPE DEVICES:
	rmt/0: QUANTUM DLT7000, Rev. 2255
	rmt/1: QUANTUM DLT7000, Rev. 1E48
	Total Devices: 2                                                                                                

2255 and 1E48 indicate the drive's firmware and are translated as follows:

• 22 represents the drives electronics firmware revision, this cannot be changed.
• 55 indicates the SCSI firmware revision designator in hexadecimal. Converting the 55 hex to decimal, results in 85. Hence the SCSI firmware for drive (rmt/0) is v85. When new SCSI firmware is downloaded, this value will change to a new hex value. For drive rmt/1 the firmware is 1E48. Hence this firmware is v72 by converting the 48 hex to decimal.

Commands Available to Find the Firmware Revision of a DLT Drive

The following commands are helpful in determining the firmware revision of a drive:

• inquiry - This command will be sent out with patches as an added help. It is not bundled in Solaris.
• probe-SCSI-all - Run this command at the ok prompt before booting the system. Run `reset-all' first to clean any status and to avoid the system hanging.
• dltprops - This command will provide the drive's f/w as well as the vendor unique page 3Eh.
• mt status - This command is found in Solaris and will indicate if a drive is alive and responding correctly.

Firmware Change Descriptions

Sometimes it is possible to find resolution to issues by reviewing the firmware change description and history. Network Storage Engineering will do its level best to provide a complete summary of change description for each firmware change. A short change history will be given under `Remarks & O/S', more detail will be given in the specific patch release with the resolved bug id number.

Firmware History for Robotics, Library/Autoloaders Matrix:

Note: All of Sun's robotics firmware are generic and support all Solaris OS revisions and Windows NT.

Legend:

• OML = original manufacturing library
• OEM = original equipment manufacturing
• active = current recommended firmware revision
• discnt = discontinued, firmware no longer recommended
• generic = common for any system, as recommended by Quantum
• Inprocess = firmware under test, field can request this firmware if they have lab units to test for certain known issues

How to Find the Robotics Firmware Revision for the L11000 Library

        Revision: Application 1.12
	Revision: Boot Block 1.11
                                                                                                      

How to Find the Robotics Firmware Revision for the L11000 Library

        Revision: Application 1.12
	Revision: Boot Block 1.11
                                                                                                      

How to Find the Drive and Robotics Firmware for the L280

Go to the GUI of the L280 and press `Next' until you see `ADMIN'. Then press `Enter' --> `Password' --> `INFO', using the `Next' button look for information similar to this example:

        Loader FW --> Enter --> v80
	Drive FW --> Enter --> 2.09
	Mech FW --> Enter --> 20
                                                                                                      

The L280 is sometimes called an autoloader because it can function as a sequential tape loader and it does not have bar code reader. But the L280 can also run as random loader by configuring it via the GUI menu tree. See the L280 user's manual Sun p/n 805-3957-10-1 for more information. The L280 does inventory of tape slots to determine which slots have tapes loaded or not.

Note: The L280 has three firmware levels for your consideration as follows.

• The DLT7000 drive has SCSI set firmware revisions such as v72, v80, v96 etc. This firmware is flash down firmware found on the DLT drive.
• The L280 robotics controller board has flash down firmware revisions such as 2.07, 2.08, 2.09, etc. The robotics controller functions as an interface for controlling the movement of the robot and communicates with the DLT drive and the Host Adapter, as to when to unload a tape and move it to and from it's slot, error report, etc.
• The third firmware for controlling the mechanical action for the L280 is in a PROM and it is a socketed IC and is designated as Mech-17, Mech-20, Mech-23, etc. This is recommended as a factory replaceable PROM only at this time.

Hint: If the `Circular' mode on an L280 is set to `ON', and the L280 is being used as a stacker or a sequential device, the L280 will overwrite the first tape once all of the tapes have been written to. To prevent this from happening, turn the `Circular' mode of the L280 to `OFF'. Then the L280 will stop after the last tape is written to.

Personality Bits for DLT Drives (EEPROM values, page 3Eh)

This personality bit list is also known as Vendor Unique page 3Eh in SCSI. In order to enhance the performance of the DLT drives with our Sun platforms and host adapters, Sun Storage Engineering has altered some of the bits from the original Quantum setting. Please see the EEPROM list for a specific drive and compare with the list given in a patch as the case may be. The `dltprops' utility will need to be used in order to view the list or alter the bits. The EEPROM bit list may change when a new firmware version is downloaded. If this happens, this will be explained in the patch and the new EEPROM values will be indicated to be updated.

Note:Take extra precautions not to make any errors in this list when changing any bit, as the functionality or performance of the drive may suffer.

Density Codes and Data Compression - What is the Difference?

"Density code selection" is a technique that allows higher or lower, bit density or `bits per inch' (bpi) recording on a tape.

There are two ways to select density:

• Using the density selection button on the drive
• Using the mode select command from the system or using the `l', `h', or `u' flags with the `mt command

"Data Compression" is the process in which an algorithm is used to minimize flux changes by removing redundant bit sequences in order to pack a high volume of bits onto a given length of tape, thereby compressing the data on a tape. When such a tape is read back, the drive must decompress the data using its decompressing algorithm, before putting it on the SCSI bus back to the host.

Two Types of Data Compression

• When the compression and decompression are done by the drive itself, this is known as hardware compression
• When the compression is done by the operating system using a certain compression utility, this is know as software compression

Also note, there are two ways to command hardware compression:

• Selecting compression using the selection button on the DLT drive (the same button is used for density selection)
• Using the mode select command from the system side. It is recommended to have only one type of compression, hardware or software

Confusion may occur as to when hardware or software compression is taking place. If the DLT drive is doing the compression using the button on the drive or by mode select from the system, this is still hardware compression. If the system is using a compression utility to compress the data before it is sent to the drive for writing, this is called software compression. Sun generally uses hardware compression, which means the drive will do the compression.

The method to select the desired density code is by using the `SCSI MODE SELECT' command or using the button on the drive and writing data to the tape from `BOT'. Please note, when the button is used to select density, it will override any selection made from the system. In other words, the button has priority over the density code command coming from the system. It is very important to understand how the density code function is designed with the DLT7000 drives. There have been many inquiries and in some cases, mis-understanding as to how the density code is implemented with the DLT7000 drives.

The DLT7000 drive has a button on the front left side of the bezel to select density codes for all of the ATL (Automated Tape Library) libraries. The exception being the L280, it has no buttons at all on the DLT drive and hence, all density command selections must come from the system. However, compression can be selected ON/OFF using the L280 GUI. Because the ATL library cannot be opened and the setting changed every time using this button, the only option is to use the `mode select' SCSI command.

Now that the differences between density codes and compression have been explained, here are the options that are available and how they are specified using UNIX density specifiers.

Caution: If a prerecorded tape is reused and write is executed from the beginning of tape (BOT) (No Append Write), all prerecorded data is lost. This includes density changes, since they only occur when writing from BOT.

Note: For a given cartridge type, only the indicated capacities are possible (DLT7000).

* - For DLT CompactTape IV, on all read and write operations, the recorded density is the density to be used. For a write from BOT, the density may be changed by one of the following:

• The density selection button
• A programmable host selection via operating system
• Native 35GB and 70GB compression, assuming the density select button or the host selection was not used

* - The DLT8000 is not released at this time, it is included in this chart for reference only.

Legend for density specifiers, system level:

        l = low
	m = medium
	h = high
	u = ultra high or compressed                                                                                                

Note: The st.conf file provides a correspondence between l, m, h, u and the hex code above. The st driver uses the hex code to instruct the drive which density code to use on writes.

To send a UNIX command to set density, use the following:

        #mt -f /dev/rmt/4u rewind                                                                                                

The above command tells the drive unit 4 to set density in compressed mode `u' and rewind.

To get to BOT condition when switching density, for example:

         /dev/rmt/0lbn                                                                                                

The above, specifies unit 0, low density, BSD behavior, and no rewind.

For more information see man pages for `mt' and `st'

Legend:

        RH = Relative Humidity
	nc = non-condensing                                                                                                

* - Listed capacities are native (No compression)

u = ultra/compressed, density codes are in hex.

e.g. /dev/rmt/[0- 127][l,m,h,u,c][b][n]

/dev/rmt/1ucn = allow compression 'u' on device /dev/rmt/1

Note DLT8000: Default density of a DLTtape IV cartridge is 40.0 GB,

native (compression OFF), or 80 GB, compressed. A density of 35.0 GB

native (compression OFF), or 70 GB, compressed OR 20.0 GB native

(compression OFF), or 40 GB, compressed, is user-selectable.

Performance Issues

Many questions had been raised in the past regarding performance. Performance greatly depends on the following.

• Optimized configuration, I/O performance
• SCSI bus utilization
• System utilization, operating system attributes
• File size and block size selected. Here file and block sizes are a function of the operating system or application software used. Block size selected can impact performance as well as the difference in effective performance between 4mb and 8mb cache modes. For the DLT7000, the best performance is achieved with large block sizes (16kbytes and above). DLT7000 drives with 4mb cache version are equipped with a Performance Mode (selectable page 3Eh, `PERFMODE=1') and when enabled, improves the effective transfer rate at some expense to the achieved capacity. Drives with 8mb cache do not include the performance mode, although the `PERFMODE=1' is visible in the EEPROM listing, it is not effective.
• Selection for `Performance mode' or `Capacity mode' on a 4mb module. This means in a DLT7000 drive with 4mb cache the `PERFMODE=1' will put out performance at some small capacity expense.
• Drive configuration if native or compressed (data compressibility)
• EEPROM bits set up
• Type of data in some cases
• Cache size in drive (4bm or 8mb). Cache determines how much data can be buffered in the drive's memory to enable a steady steam of data to the drive despite irregular transfer patterns from the SCSI bus. Irregular data could cause repositioning activity with the drive in which stop/rewind to the end-of-data/stop sequence could adversely affect overall transfer rates.
• At the SCSI level, it needs to be determined if the Host Adapter (HA) is negotiating for synchronous data transfer rate or does it default to a asynchronous transfer rate operation. Also at the SCSI level it needs to be determined if the system is negotiating for wide (16 bits) data transfer or just narrow (8 bits) data transfer. If either of the above are changed, say asynchronous and narrow, the transfer rate will be affected greatly. The DLT7000 is capable for asynchronous, synchronous, narrow or wide operations.

Asynchronous = For each ack/req, one byte of data is transferred (slow SCSI data transfer process).

Synchronous = For every req, multiple bytes are transferred and then complemented by the same number of acks (fast SCSI transfer process).

        Request (req) is generated only by the target.
	Acknowledge (ack) is generated by the host only.                                                                                                

The DLT7000 drive can transfer 5mb/s ideally and with compressed data up to 10mb/s. At 5mb/s native, ideally up to 18,000mb/hr (18gb/h) and with compression at 10mb/s this can get up to 36,000mb/h or (36gb/h). But remember these numbers are only attainable under ideal conditions.

Hint: SCSI is target driven. The target decides when to change phase.

Things to Check When Performance Seems to Suffer

• Check and confirm that throughput is below specification by more than 15-20%
• Confirm that the st.conf file is set correctly (see section on st.conf below)
• Issue an mt command:

            # mt -f /dev/rmt/xx stat                                                                                                

A good "match" from st.conf looks something like this example:

              Quantum DLT7000 tape drive:
	      sense key(0x6)= Unit Attention residual= 0 retries= 0
	      file no= 0 block no= 0
                                                                                                            

A bad match may look something like this example:

              Vendor `QUANTUM' Product `DLT7000 ' tape drive:
	      sense key(0x0)= No Additional Sense residual= 0 retries= 0
	      file no= 0 block no= 0                                                                                                

or

              SCSI tape drive:
	      sense key(0x0)= No Additional Sense residual= 0 retries= 0
	      file no= 0 block no= 0
                                                                                                            

If the DLT7000 drive is a desktop unit the `QUANTUM' will be displayed as `SUN', when the mt command is issued as noted above.

• Check for correct drive firmware and also check that the EEPROM (dltprops) settings are correct (see appropriate patch for the drive in question)

If the Performance has Degraded After Some Length of Time, Check the Following

• Check /var/adm/messages for any error reports (NBU). Too many retries may indicate bad tapes, the tape head may need cleaning or one or more drives maybe getting bad or marginal
• Check the type of media. If very old media is used, it may cause a lot of retries and error recovery
• Check that the media is handled correctly. Refer to the Media Care and Handling Guide, available at http://www.quantum.com/support/dlt/dlt_support.htm
• Replace terminator and test
• Replace SCSI host adapter and test
• Replace cables and test
• Replace specific drive causing slow transfer rate and test
• Check +5v +/- 5% and 12v +/- 10% at the drives (ideal values)

Setting SCSI Options Parameters (/etc/system file)

        008 = Global Disconnect/Reconnect
	010 = Global Linked Commands
	020 = Global Synchronous XFER Capability
	040 = Global Parity Support
	080 = Global Tagged Command Support
	100 = Global FAST SCSI Support
	200 = Global WIDE SCSI Support
	400 = Global ULTRA SCSI Support
	===
	7f8 = All SCSI Options Enabled                                                                                                

Example of /etc/system file with 7f8 set for scsi_options:

        * `modsys' modified /etc/system on `0921.1507'
	set scsi_options=0x7f8
	set maxusers=4096
	set bufhwm=10425
	set obpdebug=1
	set forthdebug=1
	set hsfs:nhsnode=1200
	set sd:sd_error_level=0
	set st:st_error_level=0                                                                                                

In nearly all cases, it may not be necessary to set the options parameter, but it may be advisable to check the `scsi_options' parameter settings, especially when customers complain of slow transfer rates or such similar issues. Please note, generally this action is not needed and it is recommended that only someone who is well informed about SCSI and UNIX (like an SSE) should attempt this effort. The scsi_options parameter is a global parameter that affects all host adapters (fas/isp/glm) that may be in the system. By default, scsi_options is set to 0x7f8 by the kernel to enable host adapter drivers to negotiate any targets to their highest SCSI speed, thus setting "set scsi_options=0x7f8" has no effect.

However, if for some reason it is found that the options parameter is set below the `7f8' value or is too restrictive, then it is possible for the system performance as a whole to have a negative effect.

The glm driver uses the following algorithm to decide how to negotiate SCSI speeds with any targets:

• Use the kernel default value of "scsi_options=0x7f8"
• If "scsi_options=XXX" is set in the /etc/system, use the value XXX to override the default
• If "target%x-scsi-options=XXX" is set in a glm.conf file (see man page for glm(7D) to set per target options), then use the value XXX to override the /etc/system setting and kernel default

If one desires to restrict the glm driver from negotiating with specific targets for the higher SCSI speeds, it's better to use the per target setting through a glm.conf file.

Notes:

• Changes to the /etc/system file should not be attempted by the general user, and it is recommended that only someone who is well informed about SCSI and UNIX (like an SSE) attempt to modify this file. Any change to the /etc/system file will require a reboot for the changes to take effect
• If "st_error_level = 0" is set in the /etc/system file and reboot, it will print diagnostic information in the /var/adm/messages file to determine if the device is configured for variable block size
• General info: After a system reset, the Open Boot PROM (OBP) has code to enable the glm to run in narrow/async mode until the glm driver is loaded. Once the glm driver is loaded, it installs firmware on the SCSI host adapter card and then enables it to negotiate to the maximum speed/width that each target supports

/kernel/drv/st.conf Issues

The st.conf file is many times overlooked as far as configuration for tape drives. When the st.conf file is not set up correctly, the transfer rate suffers because the drive will default to the generous st.conf parameters (known as Quick 11) and this is noticeable quickly when attempting to perform a backup operation.

Explanation of the "tape-config-list" Section of the st.conf file:

        {1}tape-config-list =
	{2}"DLT tape unit","{3}"DLT tape reference name","{4}"DLT tape data";
                                                                                                      

• {1} tape-config-list is a variable defined by a series of tape configuration parameters listed below
• {2}"DLT tape unit" is the vendor and product ID string for the DLT tape device. Depending on the DLT tape drive being installed, the appropriate vendor and product ID must be inserted for DLT tape unit as described in the following table:

Note:The total string character count, including spaces, must equal 15. For example:

	QUANTUM DLT7000 = 123456789ABCDEF                                                                                                

• {3}"DLT tape reference name" is a name that the system will use to identify the "DLT tape device". This reference does not change the DLT tape product ID. When the system boots, the reference name will be displayed in the list of peripheral devices recognized by the system.
• {4}"DLT tape data" is a variable containing a series of additional DLT tape device configuration information. The user selects a name in place of the "DLT tape data" string.

How to Initially Set Up the /kernel/drv/st.conf Parameters

• After power up or after an `init 0', at the ok prompt, issue a `reset-all'
• Issue a `probe-scsiscsi-all', note the response for each tape drive. All SCSI devices connected to the SCSI host adapter should respond, except the robotics. If any of the devices is not visible, there may be a basic problem such as a poor SCSI cable connection, wrong termination, bad host adapter, bad drive or even missing power. Once all SCSI devices are recognized, continue to the next step
• Issue a `boot -r' to reconfigure all of the devices (It cannot be guaranteed that a reconfiguration boot won't change any device instances or SCSI controller ID's)
• After the system boots, issue an `inquiry' command and note the drive's response, as to recognize it's reference in the st.conf file.
• Note: changing the st.conf setup may some times change the dev/rmt/xx values and some ISV may need to be reconfigured to reflect the new values.

The st.conf file is used by Sun's st (scsiscsi tape) device driver. Edit the st.conf file entries by removing the `#' (to add) or inserting a `#', in order to ignore a drive from the listing as needed.

If, for example, a DLT7000 drive is being added to a system, the output from the `inquiry' command produced something like this:

  TAPE DEVICES:
            rmt/0:   QUANTUM          DLT7000,          Rev. 2255 
            rmt/1:   QUANTUM          DLT7000,          Rev. 1E48 
        Total Devices:  2                                                                                                  

Look for the line within the tape-config-list portion of the st.conf file that corresponds to the `QUANTUM DLT7000' and remove the `#' sign at the beginning of the line. Then put a semicolon (;) at the end of the line. Be sure that all other lines end with a comma (,). This is very important, only one line in the tape-config-list portion of the file can end with a semicolon (;).

Then, look for the line with "DLT7k-data" in the second portion of the st.conf file and remove the `#' from the beginning of the line. The st.conf file lines that were just edited should look like this example:

  
#"Metrum",           "Metrum VHS Cartridge", "MetD",
 "QUANTUM DLT7000",  "Quantum DLT7000",      "DLT7k-data";  <-----(Note no `#' here
#"SUN     DLT7000",  "Sun DLT7000",          "DLT7k-data",         also see `;' end))                                    
.      
.
.       
  DLT7k-data =  1,0x38,0,0x1D639,4,0x82,0x83,0x84,0x85,3;  <-----(Note no `#' here)
.
.                                                                                                

• If installing a DLT4000 series unit, add the following line:

	  	"DLT tape data" = 1, 0x38, 0, 0x8639, 4, 0x17, 0x18, 0x82, 0x83, 3;                                                                                                

• If installing a DLT7000, add the following line:

	  	"DLT tape data" = 1, 0x38, 0, 0x8639, 4, 0x82, 0x83, 0x84, 0x85, 3;                                                                                                

• If installing a DLT8000, add the following line:

	  	"DLT tape data" = 1, 0x38, 0, 0x8639, 4, 0x84, 0x85, 0x88, 0x89, 3;                                                                                                

Notes:

• The st driver does support the DLT8000 at this time, use patch as indicated above under DLT8000 f/w.
• The standard st.conf file comes with all of the parameters set. All that needs to be done, is to remove the `#' for the drive being installed and add the semicolon (;) at the end of the appropriate line

Here is a sample of an st.conf file with some irrelevant items removed, showing the correct configuration for a DLT7000.

 st.conf file
 # Copyright (c) 1995, by Sun Microsystems, Inc.
 # All rights reserved.
 ##pragma ident	"@(#)st.conf	1.21	98/03/25 SMI"
 # This file contains configuration entries for both officially supported
 # devices of Sun Microsystems and many 3rd party devices.
 # # The officially supported devices are :
 #   "ARCHIVE Python 28454"
 #   "Quantum DLT7000"
 #   "Quantum DLT4000"
 #   "SUN     DLT7000"
 #   "SUN     DLT4000"
 #   "SUN     DLT4700"
 #   "TANDBERG TDC 4200"
 #   "TANDBERG SLR5"
 #
 # The 3rd party devices do apparently work with the configurations listed.
 # All the entries have been taken from the net and probably have worked in
 # the past, but have not been tested by Sun Microsystems.  Use these entries
 # as your starting point for generating your configuration entries.
 #
 #
 tape-config-list=        -----------------------------------------(Note no `#' here)
 #   "Emulex  MTO2",		"Emulex MT02 QIC-11/QIC-24",	"MT02",
 #   "ANRITSU DMT2120",	"Unisys 1/2\" Reel",		"ANRITSU",
 #   "Metrum",		"Metrum VHS Cartridge",		"MetD",
     "QUANTUM DLT7000",      "Quantum DLT7000", "DLT7k-data";  -----(Note no `#' here
 #   "SUN     DLT7000",      "Sun DLT7000",     "DLT7k-data",         also see `;' end))
 #   "Quantum DLT4000",      "Quantum DLT4000", "DLT-data",
 #   "SUN     DLT4000",      "DLT4000",         "DLT-data",
 #   "SUN     DLT4700",      "DLT4700 Library", "DLT-data",
 #   "R-BYTE  RB100",	"R-Byte Whozits",		"DAT",
 #   "SONY    SDT-5000",	"SONY 4mm DAT",			"DAT",
 #DLT2	 =	1,0x38,0,0xd639,4,0x17,0x18,0x80,0x81,2;
 #DLT-data =   	1,0x38,0,0xD639,4,0x80,0x81,0x82,0x83,2; 
  DLT7k-data = 	1,0x38,0,0x1D639,4,0x82,0x83,0x84,0x85,3; ----(Note no `#' here)
 #EXB-2501	=	1,0x28,1024,0x442,1,0x00,0;
 #EXB-8200	=	1,0x28,0,0x8c79,1,0x00,0;
 #WtQIC		=	1,0x32,512,0x467a,1,0x00,0;
 name="st"scsiss="scsi"
     target=0 lun=0;                                                                                                  

Note: The same `DLT7k-data' name should be used for {3}"DLT tape reference name" and {4}"DLT tape data".

Explanation of Parameters for the st.conf File

The "DLT tape data" field in the st.conf file contains 10 parameters and are described as follows:

              [1]  [2]  [3]  [4]    [5] [6]   [7]   [8]   [9]  [10]
DLT7k-data =   1, 0x38,  0, 0x8639,  4, 0x82, 0x83, 0x84, 0x85,  3;                                                                                                

• [1] This `1' is the version number and should not be changed.
• [2] This `0x38' designates the DLT tape drive as "other SCSI drive". This is defined in /usr/include/sys/mtio.h.

Note: Use 0x36 in place of the 0x38 value for Solaris 2.5.1 configurations and below. In Solaris 2.6, it may be necessary to apply the Solaris 2.6 recommended patch cluster in order to use the 0x38 value, but the 0x36 value should also work.

• [3] This `0' is the block size. Since the DLT tape drive?uses variable block size, this value should be zero.
• [4] This `0x8639' is an addition of values (hex) shown below, that represent selected device options. The table below lists some of the suggested options and the corresponding value:

The `st' man page has more information about these and other possible device options. For certain applications, it may be necessary to consider adding or removing one or more of the device options. But generally, the default works well.

• [5] The, `4', defines the number of densities. The maximum definable number of densities is 4 (l,m,h,u).
• [6],[7],[8],[9] are used for system selection of tape densities. Although the entries described above are recommended, other density entries are possible. The following list describes the density codes used with this set of parameters. Refer to the product manual for the drive being installed for additional density code information. Again the default entries work fine, so it is not recommended to change any of them.
• 0x17 - 2.6 GB, 42500 MFM bpi uncompressed mode, using DLTtape[tm] III (CompacTape[tm] III) cartridge. In the case of an installed DLT2000XT, DLT2500XT, DLT2700XT, DLT4000, DLT4500, DLT4700 or DLT7000 loaded with a DLTtape[tm] IIIXT (CompacTape IIIXT) cartridge or an installed DLT4000, DLT4500,DLT4700 or DLT7000 loaded with a DLTtape[tm] IV (CompacTape[tm] IV) cartridge, this density code is invalid and will default the tape drive to the optimal densities for the loaded tape cartridge.
• 0x18 - 6.0 GB, 42500 bpi uncompressed mode, using a DLTtape III (CompacTape III) cartridge. In the case of an installed DLT2000XT, DLT2500XT, DLT2700XT, DLT4000, DLT4500, DLT4700 or DLT7000 loaded with a DLTtape IIIXT (CompacTape IIIXT) cartridge or an installed DLT4000, DLT4500, DLT4700 or DLT7000 loaded with a DLTtape IV (CompacTape IV) cartridge, this density code is invalid and will default the tape drive to the optimal densities for the loaded tape cartridge.
• 0x80 - 62500 bpi, uncompressed mode, vendor unique density code for DLT2000, DLT4000 series units and DLT7000 drives. For an installed DLT2000, DLT2500, DLT2700, DLT4000 series unit or DLT7000 drive loaded with DLTtape III (CompacTape III) cartridge, the cartridge capacity is 10 GB; for an installed DLT2000XT, DLT2500XT, DLT2700XT, DLT4000 series unit or DLT7000 drive loaded with a DLTtape IIIXT (CompacTape IIIXT) cartridge, the cartridge capacity is 15 GB.
• 0x81 - 62500 bpi, compressed mode, vendor unique density code for DLT2000, DLT4000 series units and DLT7000 drives. For an installed DLT2000, DLT2500, DLT2700, DLT4000 series unit or DLT7000 drive loaded with DLT DLT2700XT, DLT4000 series unit or DLT7000 drive loaded with a DLTtape IIIXT (CompacTape IIIXT) cartridge, the cartridge capacity is 30 GB.
• 0x82 - 81633 bpi, uncompressed mode, vendor unique density code for DLT4000 series units and DLT7000 drives loaded with DLTtape IV (CompacTape IV) tape cartridge.
• 0x83 - 81633 bpi compressed mode, vendor unique density code for DLT4000 series units and DLT7000 drives loaded with DLTtape IV (CompacTape IV) tape cartridge.
• 0x84 - 35 GB, 85937 bpi, uncompressed mode, vendor unique density code DLT7000 drives loaded with DLTtape IV (CompacTape IV) tape cartridge.
• 0x85 - 70 GB, 85937 bpi compressed mode, vendor unique density code for DLT7000 drives loaded with DLTtape IV (CompacTape IV) tape cartridge.
• 0x88 - 40 GB, 98250 bpi uncompressed mode, vendor unique density code for DLT8000 drives loaded with DLTtape IV (CompacTape IV) tape cartridge.
• 0x89 - 80 GB, 98250 bpi compressed mode, vendor unique density code for DLT8000 drives loaded with DLTtape IV (CompacTape IV) tape cartridge.
• [10] The `3' defines which density the system will use as the default density. The sixth, seventh, eighth and ninth parameters in the "DLT tape data" string are referenced by the system as 0, 1, 2 and 3, respectively. The 3 value for the tenth parameter selects the 0x85 density code as the system default density in this example for DLT7000 drive.

Note: For more information, check the st.conf man page.

Windows NT and DLT Drives

For Windows NT application, only the generic type of firmware can be used with the DLT drives. The Sun-specific firmware used in the desktop flexipack, cannot be used and the drive fails to be recognized by NT configurator.

Note: At this time drives that have the Sun version of the firmware, will not accept the generic firmware if attempt is made to download the generic firmware. This is due to a lock bit set in the drive not to allow a generic firmware to be download. This will change in the future to make all our DLT drive able to receive generic firmware and be able to be recognized by win-NT. Also our DLT firmware, in the EEPROM page, certain bits are set as such in order to make the drives more tolerable to various speed scsi host adapters.

Independent Software Vendors (ISV)/Backup Utilities Matrix

Tape Cartridges Handling and Care

It is very important to educate users on correct tape cartridge handling procedures. Quantum has created a complete tape cartridge handling procedure that is strongly recommended to all customers or computer site supervisors, using any of the DLT tapes. To get a copy of the tape cartridge handling procedure, go to the Quantum web page at http://www.quantum.com/support/dlt/dlt_support.htm The tape handling procedure is included with most new DLT firmware patches that have been released. In general, avoid bringing the tape cartridge close to any magnet and when passing through airport security, it is better to pass the recorded tape through the X-ray machines with your luggage instead of the individual magnetic sensors used for people to pass through. X-ray's do not affect magnetic recodings while magnetic sensors may.

Note: Cleaning Tape III is good for about 20 cleanings. The DLT drives do not require periodic cleaning. If the clean LED is lit up and stays on, even when other tapes are loaded, this could be an indication for head cleaning. Once the drive is cleaned do not clean repetitively as this will only damage the head. If the clean LED comes on too frequently, either the tapes being used are bad or the drive requires another type of service (Example: need to upgrade to the latest firmware revision or the drive may be marginal and may need replacing). Also, if the ISV has its cleaning function option enabled, then the library's auto-clean must be disabled.

Here are some simple rules to follow:

• `TAPE light is ON'** - indicate the drive detected one of the following conditions:
• CALIBRATION ERROR
• CALIBRATION SIGNAL/S ARE MARGINAL
• MEDIA READ ERROR
• MEDIA WRITE ERROR

** DO NOT IGNORE THIS INDICATOR, BACKUP FAILURE MAY RESULT

To clear this indicator, try the following first:

• Use a different data cartridge
• unload and reload the same data cartridge

If the light still remains "ON":

• Unload the data cartridge
• Load the DLT Cleaning Tape, it will automatically:
• Perform a head cleaning routine
• Unload the tape
• Turn the light "OFF"
• The cleaning cartridge should then be removed and mark the label on the cleaning cartridge to indicate one usage, then load the data cartridge

If the light REMAINS "ON" after the cleaning routine has been run:

• The cartridge has expired (20 passes have been run), run another DLT cleaning tape

Two passes of the DLT cleaning tape should be run and a different data cartridge should be tried before it is decided that the DLT tape drive needs service. Repeat occurrences of the "USE CLEANING TAPE" light with different data cartridges may indicate a problem that requires service.

Quick Cartridge Inspection - What to Look for

The symptoms for a bad cartridge that could cause drop leader are:

• Swallowed cartridge leader or broken tape
• Broken leader loop
• Media wrapped too loosely

Drop Leader Issues with DLT Drives

For the DLT7000 drives, firmware version v85 or later have been released to help with `drop leader' issues. However, it has been observed, that the following aspects contribute to `drop leader' issues.

• Mishandling of cartridges. To help resolve this issue, it is highly recommended that users become familiar with a document from Quantum on how to handle and care for the DLT tape cartridges. See also the section of this troubleshooting aid on `Tape Cartridges Handling and Care'
• When a `drop leader' occurs on a drive, this most probably, could have been caused by a bad or worn-out cartridge or a worn out `leader tape' inside the drive itself. The term `drop leader' means that the `leader tape' did not hook back up to its post when the cartridge was ejected. Rather, it is now wound completely on to the take-up reel and there will be nothing to guide and pull the tape initially from the cartridge when loading is to occur

If the cartridge is the cause for the `drop leader', the user has to pay attention and root out the cartridge immediately before this same cartridge is attempted to be loaded into another drive. If an attempt is made to load such a cartridge into a good drive, trying to recover data, the same `drop leader' may occur on the good drive. Sometimes, users may complain that they continue to get `drop leaders' after replacing the drive(s), when it is really the bad tape cartridge left in the library slots causing the leader drops. It is recommended that when a `drop leader' occurs in a drive, that all of the cartridges in the library be carefully examined before continuing operation.

These are the things to look for when examining a cartridge:

• Swallowed cartridge leader or broken tape
• Broken leader loop (loop on the cartridge tape tip itself may be broken)
• Media wrapped too loosely

It takes about 10 seconds or so to examine a cartridge. A `swallowed leader', is when the `loop formed tip' of the tape disappears inside the cartridge and the leader will have nothing to hook onto and pull the tape out and wind it on the take up reel. If a `drop leader' occurs, it is recommended that the drive be replaced and sent for reattachement of the leader or replacement. The leader is found inside the drive and it is approximately 14 inches long. It is made of a very tough black plastic material the same width as the tape and has a kind of hook type formation at its tip to hook onto the tape loop and thread the tape on the take up reel.

This is how a good `leader tape' looks:

This is a worn out leader with a broken hook tip:

It is easy to recognize when a leader is dropped. With the tape cartridge removed look inside the drive through the cartridge gate. If the leader is still attached, a black tape leader coming from the left and attached to a post or hook can be seen. If the leader is dropped, there will be no sign of any black tape leader anywhere, since the tape leader will have been wrapped around the take up reel. Gain experience by looking at a good drive and see how the leader is attached. Generally speaking, with v85 or later firmware and good cartridge handling by the user, `drop leader' issues should become a very rare occurrence. It has been asked if the leader tape can be replaced or reattached in the field. It is not difficult to replace or reattach a leader. An experienced person using simple tools and a spring hook can replace or reattach a dropped leader in about 5 minutes after removing the top dust cover and breaking the warranty seal at the back. It is not recommended to work on a dropped leader in the field if a replacement drive can be obtained within a few hours because of possible warranty issues. The decision would be left to the user or depot manager to consider warranty issues, experience and criticality of the situation.

Utilities (Software) NOTE: Patch 108409-01 has not been released yet. New Utilities are being evaluated.

The following utilities and commands are available and will also be supplied with every firmware patch as needed. These commands and utilities can also be found in the Tape Command Pool & Utilities (TCP & U) patch 108409-01. This is an important patch to remember, since it has all of the handy commands, utilities, and a README file all encompassed within this one patch for ease of use and accessibility. Later verions of patch 108409-01 will include diagnostic utilities for troubleshooting. Below is a listing of the commands and utilities included in patch 108409-01.

Patches & BugIDs - Matrixes for Libraries & Autoloaders ONLY

Patches & BugIDs - Matrix for Libraries & Autoloaders, DLT Drives ONLY

DLT Drive Serial and Model Number Format Definitions

Serial Number Format

Example serial number:

        xx 7 23 S 0246                                                                                                

CX = Colorado Springs USA
SH = Shrewsbury USA                                                                                                                                                                                                

F = DLT2000
T = DLT2000XT
M = DLT4000
R = DLT4000E
S = DLT7000
P = DLT8000                                                                                                                                                                                                

Model Number Format

Example Model Number:

        THNPQ -- SY
                                                                                                      

3 = 15/30GB DLT2000XT
4 = 10/20GB DLT2000
5 = 20/40GB DLT4000
6 = 35/70GB DLT7000
8 = 40/80GB DLT8000
X = Media accessories                                                                                                                                                                                                

A = Embedded drive
B = Table top
L = Library drive
X = LDR/LIB drive (no handle motor)                                                                                                                                                                                                

A = Single-ended (SE) (4 pin power)
B = Differential (HVD) (4 pin power)
C = Single-ended (SE) (14 pin power)
D = Differential (HVD) (14 pin power)
E = DLT7000 Single-ended with 8mb cache
F = DLT7000 Differential with 8mb cache                                                                                                                                                                                                

A = Single-end (4/14 pin power)
B = Differential (4/14 pin power)                                                                                                                                                                                                

Note: For `Q' definition, E and F designate a DLT7000 with 8mb cache. When nothing is listed, it indicates the drive has 4mb cache. The DLT4000 drives have 4mb cache.

Error Codes

The `Axxx' Error codes generated by the drive are stored in the drive itself and can be read out using the Quantum's DLTtools diagnostic utility. This utility and manual can be downloaded from Quantum's web page at:

http://www.quantum.com/support/csr/software/csr_software.htm

WARNING: Any consequences of using this software are the sole responsibility of the user (This utility is DOS-based and does not run on Sun platforms).

The drive will store the last 14 events.

Drive Level Internal Error Codes

To extract the above error codes from the drives log page 07, the following will be needed:

• Obtain the Quantum diagnostic utility and load on to a PC or laptop
• Connect the DLT drive via differential SCSI host adapter to a PC or laptop. If only a single ended host adapter is available, then a single ended to differential bridge will be needed. If the DLT is single ended, then a single ended host adapter will be needed to connect the PC or laptop to the drive.
• Run the utility to get to the menu
• At the menu go to Pages --> Log --> Display, then enter 07 and hit return. The log page 07h will display the error log. Refer to the Error codes description portion of the troubleshooting guide to decipher what the error codes mean

SCSI, System Level Status Codes

SCSI, System Level Sense Keys

Legend (SCSI level error codes definitions):

• SK = Sense Key
• ASC = Additional Sense Code
• ASCQ = Additional Sense Code Qualifier
• CDB = Command Descriptor Block (the command sent to the drive)