Chapter 5. DLT Drive Operation and Troubleshooting

This chapter explains

Tape Cartridges

This section explains

  • tape compatibility

  • tape cartridge care

  • tape cartridge write protection

Note: To purchase additional data or cleaning tapes for your DLT drive, contact your Silicon Graphics sales or service representative for information.

Tape Compatibility

The DLT7000 drive normally uses the DLTtape IV cartridge. This black plastic cartridge stores up to 35 GB of native (uncompressed) data, or 70 GB of compression mode data. The DLT7000 can also read and write the DLTtape IIIxt cartridge (15 GB native and 30 GB compressed), or the DLTtape III cartridge (10 GB native or 20 GB compressed).

The tape cartridges for the DLT2000XT drive are the white DLTtape IIIxt cartridges. The DLT2000XT drive stores and reads up to 15 GB native and 30 GB compressed data on each tape. Note that the DLT2000XT drive will not write more than this amount even if you use a higher capacity cartridge. Never use the DLTtape IV cartridge in a 2000XT drive.

The DLT7000 drive is capable of backward-format compatibility with previous generations of DLT tape cartridges, providing forward and backward data interchange with systems having older drives. For example, a system with a DLT2000 tape drive can interchange data with a system having a DLT7000 drive by using a CompacTape III cartridge.

Tape drives are not forward-compatible with respect to tape cartridges; for example, the DLT2000 tape drive cannot read DLTtape IV or DLTtape IIIxt cartridges.

Tape Cartridge Care

To make tape cartridges last as long as possible, store them in a clean environment. Follow these guidelines for storing and using the tapes:

  • Store cartridges in temperatures between 41 and 113˚F (5-45˚C). For longer cartridge life, always store cartridges in their plastic containers in room environment conditions of 65˚F to 80˚F (18˚C to 26˚C).

  • Keep tape cartridges out of direct sunlight and away from heat sources.

  • Stabilize the tape if it has been exposed to extreme heat or cold by leaving it at operating room temperature for the same period of time (up to 24 hours).

  • Store tape cartridges in a dust-free environment with the relative humidity between 20% and 80%. For longer cartridge life, store cartridges at 20% to 60% relative humidity.

  • Do not apply labels to the top or bottom of tape cartridges, because incorrectly placed labels can cause cartridge jams. Place labels only in the slide-in slot on the front of the cartridge that is designed to accommodate them. Do not use adhesive tapes on top of the labels.

Observe the following precautions when handling or storing a tape:

  • Never place or store cartridges near electromagnetic sources such as terminals, electric motors, or video or X-ray equipment. Data on a tape may be altered or corrupted if it is placed in such an environment.

  • Do not leave a cartridge in a vehicle parked in the sun.

  • Never handle the cartridge roughly or drop it. You might displace the tape leader, make the cartridge unusable, or damage the DLT drive.

  • If you do drop a tape cartridge:

    • Examine the cartridge case for any damage, dents, cracks, etc. Never use a damaged tape cartridge.

    • Shake the cartridge to check for loose or broken internal parts; do not use the tape if it has parts rattling inside.

Tape Cartridge Write Protection

The tape cartridge has a write-protect switch that functions as follows:

  • When the write-protect switch is moved to the left, the tape is write-protected and the orange indicator shows.

  • When the write-protect switch is moved to the right, the tape is write-enabled and the orange indicator is hidden.

Figure 5-1 shows the write-protect switch and the indicator.

Figure 5-1. Tape Cartridge Write-Protect Switch

Note: Do not move the write-protect switch during tape operation.

DLT Drive Operation

This section explains

  • drive LEDs

  • loading and removing a tape cartridge

  • tape operation

  • tape data block transfer sizing

Drive LEDs and Controls

The DLT tape drives have front-mounted LEDs that indicate the status of the unit. Figure 5-2 shows the front panel of the DLT20000XT and 7000 drives.

The DLT7000 front bezel has a density select button on the lower left that is not supported (and does not function) in Silicon Graphics systems. All DLT7000 density selection changes are made through software.

Note: For information on the power-on self test LED sequences, see “Using the Power-On Self-Test” in Chapter 3.

Figure 5-2. DLT2000XT and 7000 Front Panels

Table 5-1 summarizes front panel LEDs.

Table 5-1. DLT Drive Right Front LEDs and Controls




All LEDs

Light up in sequence from top to bottom

Drive is starting power-on self-test (POST).


Remain on

Drive is running POST.



Error condition; press the Unload button and the error condition should clear.

Write Protected (orange)

Remains on

Data cartridge is write-protected.



Data cartridge is write-enabled.

Tape in Use (yellow)


Tape is moving.


Remains on

Tape is loaded and ready for use.

Use Cleaning Tape (yellow)

Remains on

Drive head needs cleaning or the tape is bad.


Remains on after you unload the cleaning tape

Cleaning tape attempted to clean the drive head, but the tape expired, so cleaning was not completed.


Turns on again when you reinsert cartridge after cleaning

Possible data cartridge problem; try loading another one.



Cleaning is complete, or cleaning is unnecessary.

Operate Handle (green)

Remains on

After beeper sounds, it's OK to operate the cartridge load/unload handle.



Do not operate the cartridge load/unload handle.



Drop handle to finish POST.

Table 5-2 summarizes middle front panel LEDs on the 2000XT.

Table 5-2. DLT2000XT Tape Drive Front Panel LEDs and Controls




To Load


Wait until the light goes off.


Open this Handle

If the green Operate Handle light is on and the beeper has sounded, open the handle.


Insert Tape

It's OK to insert the tape cartridge.


Close this Handle

Close the handle.

To Unload

Press Button

Push the Unload button.



Wait until the light goes off.


Open this Handle

If the green Operate Handle light is on and the beeper has sounded, open the handle.


Remove Tape

It's OK to remove the tape cartridge.

After initialization, the drive is in one of the states shown in Table 5-3.

Table 5-3. Drive States

Drive State

Indicator Displays and Actions

No cartridge present

Yellow Tape in Use LED turns off; green Operate Handle LED turns on.

Handle unlatches; drive beeps momentarily.

You can raise the handle and insert a cartridge.

Cartridge present, handle down

The drive loads the cartridge. The drive is ready for use.

Cartridge present, handle up (not recommended)

No cartridge present, handle could be up (not recommended)

Yellow Tape in Use LED turns off; green Operate Handle LED flashes. When you lower the handle, the cartridge loads.

Drive detects error condition

Right or left panel LEDs blink repeatedly.

Try to unload the cartridge and reinitialize the drive by pressing the Unload button, or power-cycle the drive (turn the drive power off and then on again).

The right or left panel LEDs stop blinking and the drive attempts to reinitialize. If the self-test is successful, the LEDs remain on (up to 15 seconds), and then turn off.

Loading and Removing a Tape Cartridge

Load the tape cartridge as follows:

  1. When the DLT drive beeps and the green Operate Handle LED is on steadily, lift up the cartridge load/unload handle, as shown in Figure 5-3.

  2. Hold the tape with the write-protect switch closest to you and insert the cartridge into the drive.

  3. Push the handle closed.

    Figure 5-3. Loading a Tape Cartridge in the DLT Drive

The green Operate Handle LED goes off and the yellow Tape in Use LED blinks to indicate that the tape is loading. When the tape is at the beginning-of-tape (BOT) marker, the yellow Tape in Use LED glows steadily. The tape is now ready for use.

When the tape is being read, written, or rewound, the yellow Tape in Use LED blinks (see Table 5-2).

Remove a tape cartridge as follows:

  1. When the yellow Tape in Use LED glows steadily, press the Unload button; the LED starts to blink.

  2. When the green Operate Handle LED comes on, lift the handle and remove the tape.

  3. Return the tape to its plastic container.

Note: The green Operate Handle LED must be on before you open the handle or remove a tape. Always remove the tape cartridge from the DLT before turning off power to the drive.

Tape Operation

You can select compression from the host using the appropriate SCSI tape interface; see the tps reference page for more information. The default selection is the native tape density for the cartridge type you insert.

For interchange compatibility with earlier drives, the tape drive can write lower-capacity tape formats. On a write from BOT, the tape drive automatically reformats the tape cartridge to match the maximum native (uncompressed) capacity the drive can write on the cartridge. The drive automatically reads the media regardless of the format.

Note: After a bus reset, the tape drive responds within a bus selection timeout period. Although the system manager backup and restore tool may report the DLT drive as “unknown,” it works correctly.

Tape Data Block Transfer Sizing

The DLT drive default data block transfer size is 4KB (4096 bytes). To achieve better performance, adjust block size to 32K bytes or higher when using a fixed block device.

Depending on your particular applications, the fullest data transfer performance (throughput) can be obtained by specifying a variable block size during backups or other data transfer operations.

To use the variable setting when performing backups, use the v addition to the device identifier when specifying data for backup.

For example, the following command copies all files in the current directory to a DLT drive that is installed as SCSI unit 6 on controller 1:

% tar -cvf /dev/mt/tps1d6v * 

The v added at the end of the device identifier tps1d6 allows the system to vary the block transfer size to achieve the most efficient transfer of data.

The addition of the v can also provide variable block size transfers for use with other backup commands such as cpio, dd, dump, or restore. See the reference (man) page for a particular data transfer command for additional information on its use.

Cleaning the Drive Head

When a drive head is dirty and needs cleaning, or the data cartridge is bad, the Use Cleaning Tape LED lights on the front of the DLT drive.

To clean a drive, use only an approved cleaning cartridge (see Figure 5-4). You can use a DLT cleaning cartridge approximately 20 times before you must replace it. The cleaning cartridge and data cartridges are always different colors.

Figure 5-4. Cleaning Cartridge

Every time you use the cleaning cartridge, the drive uses a new, unused portion of the tape. After approximately 20 cleanings, the entire tape is used and you must obtain a new cartridge. Therefore, it is a good idea to keep track of the number of times you use each cartridge.

To clean a DLT drive, follow these steps:

  1. Load the cleaning cartridge into the drive and close the handle. The drive automatically detects that the cartridge is a cleaning cartridge; it buzzes, then loads and runs the cartridge. The Tape in Use LED lights.

    After the cleaning is complete, the Use Cleaning Tape LED goes dark, and the beeper sounds.

  2. When the cleaning cycle is finished, press the Unload button and wait for the green Operate Handle LED to light before opening the handle.

  3. Remove the cartridge from the DLT tape drive unit.

  4. Make a note in a log or on the cartridge itself that you used the cleaning cartridge.

Note: Do not attempt to remove the cleaning tape from the drive while it is going through the cleaning cycle.

If a data cartridge causes the Use Cleaning Tape LED to light frequently, the data cartridge may be damaged. Back up this data onto another cartridge and discard the old cartridge.

Troubleshooting DLT Drives

The following sections explain how to identify and troubleshoot simple problems with a DLT7000 or 2000XT drive after it has been installed.

Topics covered include

  • solving problems

  • removing a jammed tape cartridge

  • updating firmware from a tape cartridge

Solving Basic Problems on the DLT Drive

This section lists some malfunctions that might occur with the DLT7000 or 2000XT tape drive, and some simple things you can do to resolve them.

Note: When a problem is beyond the general scope of an end user or administrator, contact your service provider.

A number of basic problems you might encounter could cause the DLT drive to be partly or completely nonfunctional:

  • The hardware may not be connected properly.

  • The Origin Vault may be powered off.

  • The operating system may not be configured (updated) to recognize the DLT drive.

  • SCSI cabling or termination may be incorrect.

  • SCSI device IDs may be improperly configured.

  • The SCSI cable may be pinched or damaged.

  • The Origin200 power supply may have problems.

  • The Origin Vault power supply may be malfunctioning or dead.

If you suspect the problem originates with a faulty power supply in the Origin Vault, see the Origin Vault Owner's Guide (P/N 007-3455-xxx). If the DLT is mounted in an Origin200 system, see the Origin200 Owner's Guide (P/N 007-3415-xxx).

The easiest way to tell if the host system sees a DLT drive you have installed is to use the hinv (hardware inventory) command. The hinv command lists all the information contained in the host system's hardware inventory table. This table is generated and updated each time the host system is rebooted. If the system was not fully rebooted after the new DLT drive was installed, the inventory table will not have information about it.

Using hinv -c tape

The hinv -c tape inquiry to a deskside or rackmount system provides information on every tape drive connected to that host. Use the command to determine if the DLT drive(s) you installed are recognized by the host.

%hinv -c tape
  Tape drive: unit 5 on SCSI controller 7: 8mm(8500) cartridge
  Tape drive: unit 6 on SCSI controller 6: DLT
  Tape drive: unit 5 on SCSI controller 6: DLT

Tip: If you installed a DLT drive, and the hinv list shows that the host system does not see it attached to any SCSI controller, read the next section “What to Do If hinv Does Not See the Tape Drive.” Also see Table 5-4 for additional solutions.

What to Do If hinv Does Not See the Tape Drive

Under certain circumstances, the drive may not show up in the hinv listing after you connect the DLT drive to the host system. Some common causes for this problem are listed in the first two columns of Table 5-1. If none of the solutions listed in Table 5-4 are applicable, try the following procedures:

  1. Confirm that the host system is running operating system release 6.4 or later. At the system prompt, enter

    % uname -r 

If the host is running an IRIX operating system release older than those listed, the system will not recognize the DLT7000 tape drive and may not recognize the 2000XT drive. Upgrade the host system to the appropriate release. Contact your sales or service representative if a copy of the proper operating system is not available.

In the output, look for the newly installed DLT drive. If the tape drive is not recognized, recheck all the solutions listed in the first two columns of Table 5-4.

  1. If you cannot read or write tapes in the DLT drive even though it is listed in hinv, it is possible that the device driver was not properly created during system startup. You can determine the status of the available system drivers by entering

    % ls /dev/mt 

  2. To determine the status of a DLT drive, enter

    % mt stat

See the mt and mtio reference (man) pages for additional information on these topics.

  1. You can try manually making the device by becoming root and using the following commands:

    % su 
    # cd /dev 
    # MAKEDEV tape
    # exit

  2. Reboot the host system and try hinv -c tape again. After trying all the troubleshooting tips in this section and checking all the solutions listed in Table 5-4, contact your system administrator or service provider if the system still does not recognize or allow access to the DLT drive.

Symptoms and Possible Solutions

Table 5-4 lists general potential problems and possible solutions. If none of the offered solutions helps, consult your system administrator or service provider.

Table 5-4. General DLT Drive Problem Symptoms and Possible Solutions


Possible Solutions





The host does not see an externally connected tape drive.

Is the SCSI cable connection secure?

Is the external SCSI cable pinched or damaged?

Is the DLT drive's SCSI ID set properly?

Is the Origin Vault (or desktop unit) powered on?

Is the proper SCSI terminator (if applicable) installed?

The host does not see an internally-
mounted DLT drive.

Is the DLT drive's power cable plugged securely?

Is the drive's SCSI cable connector plugged in?

Are there any bent pins on the SCSI connector?

Is the DLT drive's SCSI ID set properly?

Is the DLT carrier completely seated in the drive bay?

The host is registering numerous SCSI errors.

Are the SCSI cables firmly connected? Are there any bent SCSI pins?

Is the proper SCSI terminator in place?

Is the Vault's SCSI cable within acceptable length limits?

Are there any duplicate SCSI IDs on the SCSI bus?

Is there more than one additional device connected to the DLT's SCSI bus?

External SCSI device or cable diagnostic fails at power on.

Was the DLT drive powered on before the host system?

Are the SCSI cables firmly connected to the DLT drive and host?

Are there any bent SCSI pins on the connectors?




Error message “...resetting SCSI bus” after power interruption or power on.

Was the DLT drive powered on before the host system?

Was there an unplanned power interruption to the DLT drive?




If none of the offered solutions helps, consult your system administrator or service provider.

Removing a Jammed Tape Cartridge

The following instructions are intended to help you if a tape cartridge becomes jammed in the DLT drive and will not unload. Before calling your service provider, try the following:

  1. If the tape fails to unload, power the unit off and then on again, and push the Unload button again.

  2. Power the unit off and on again while pressing on the Unload button.

If these steps fail, contact your system administrator or service provider for assistance.