NetWorker: Troubleshooting Tape Library Detection Problems in NetWorker

Summary: This article is intended to assist Support and NetWorker Administrators in determining the causes for a host's inability to detect a library.

This article applies to This article does not apply to This article is not tied to any specific product. Not all product versions are identified in this article.
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Instructions

If the library was working previously, and suddenly is not, consider the last known change as the likely cause:

  • Unhandled change in library address following reboot, rediscovery, and renaming of device
  • Possible damage due to power surge, outage, or other environmental event
  • Failure events or reconfiguration of transport hardware
  • Installation, change, or deletion of software or drivers pertaining to transport or robotics

If the library has never worked, confirm that the hardware is supported in the NetWorker Hardware Compatibility Guide (Requires Dell Support Account Sign-In).
 

  • Unable to detect tape library installation on NetWorker Storage Node or Server
  • Unable to backup data due to unusable backup hardware.

To diagnose library‑detection failures, first consider any recent changes. Next, break down the discovery process from its lowest levels and test each stage.

Sometimes it is desirable to move forward to a more evolved stage of discovery, based on the available evidence. If Host A fails to detect the robot while Host B succeeds, the robot is likely not at fault. The hosts may use different switches, making that the first area to investigate. Other differences in this example include the host itself, possibly operating system, HBA, zoning, cabling, so on.

If the host detected the robot before the issue, focus on items most likely to have changed. Investigate failures or known configuration changes after the event.

Use the following commands to first establish if the Operating System can detect the library. Always, ensure that Operating System patches are up to date, especially concerning storage.

NOTE: The easiest way to gather a comprehensive initial dataset including the above is to run nsrget -o:d on affected server and nodes.
CAUTION: DO NOT use the -o:d on any host with tapes where the tapes are busy writing. You can check this from the NetWorker Management Console (NMC) under Monitoring -> Devices.

The following article provides information about getting and using NSRGET: NetWorker: How to Use the NSRGet NetWorker Data Collection Tool

Library Detection: Operating System:

  • Windows: Devices not detected by the Plug-and-Play (PnP) subsystem may not be accessible to NetWorker. There is never an instance of a library without a driver, as a generic driver exists even if a vendor driver is not installed. StorPort is the low-level Windows storage driver component which should be checked for currency.
devmgmt.msc (Device Manager)
devcon drivernodes *CHANGER*
  • Linux: Show which SCSI-class devices the subsystem has detected and enumerated. Linux uses the sg driver for Libraries unless IBM's Atape driver is installed (not recommended).
cat /proc/scsi/scsi (show detected libraries)
echo "- - -" > /sys/class/scsi_host/host#/scan (force redetection)
 
  • Solaris: cfgadm or luxadm port / dump_map commands can both enumerate a Library device. Failing this, update_drv can be used to ensure both detection and the ability to attach an sgen driver instance.
cfgadm -lavo show_FCP_dev
for FCI in `luxadm -e port | cut -f1`; do luxadm -e dump_map $FCI; done
rm -f /dev/scsi/changer/*; update_drv -f sgen -v
 
  • AIX: Use cfgmgr under most circumstances; if Atape driver is in use, use lsdev. In this case - ensure the Atape smc driver is listed as 'defined' and not 'available' (which causes conflicts).
cfgmgr -v | grep -i changer
lsdev -Cc tape
rmdev -l smc0 (if lsdev shows it to be available)
 
  • HP-UX: ioscan is the only command required to enumerate changer-class devices.
ioscan -FnkC autoch

For the NetWorker inquire command (below) to succeed, you may need to remove the temporary device discovery cache file:

rm -f /tmp/lgto_scsi_devlist
 
  • OpenVMS: Use these commands to verify connectivity:
mcr sysman IO AUTOCONFIGURE
show device gk/full
  • NetWorker: These commands are provided as reference and generally perform at a higher level than the operating system commands provided above. They may be useful in attempting to diagnose a lower-level problem by providing additional information or errors as hints toward the problem at hand, but they are not expected to succeed if lower-level operations are failing.
inquire -lc
lusbinfo -v
changers
dvdetect -dlV -D9
 
NOTE: lusbinfo and changers may not exist on all platforms. If wanted, you may increase debug levels by setting the environment variable LUS_DEBUG:

UNIX: export LUS_DEBUG=9
Windows: set LUS_DEBUG=9
AIX: lusdebug ffff
Also try: SJI_DEBUG=9, SCSI_DEBUG=9, JBDEBUG=9 

Additional Information

Ensure that you understand that robotics issues which are shown to be outside of NetWorker's scope as an application (read: cannot be detected using standard Operation System methods) are not within the scope of NetWorker support. 
For more information, see: NetWorker: Troubleshooting Tape Library Problems in NetWorker

Support  can provide guidance using the criteria above, but we do not have OS, HBA, or robotics vendor resources. This limitation can lead to prolonged, unsuccessful troubleshooting.

Affected Products

NetWorker Series
Article Properties
Article Number: 000079269
Article Type: How To
Last Modified: 23 كانون الثاني 2026
Version:  4
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