NetWorker: Red Hat 8.10 / 9.4: I/O errors accessing tape

• Recent install or upgrade to Red Hat Enterprise Linux 9.4 or 8.10
• Errors attempting to configure a tape library, running inquire, or mounting or labeling tapes:

  /dev/st0: Input/output error
  scsidev@2.0.1: Input/output error

Red Hat has a bug filed for the problem. Contact Red Hat Support for details on RHEL-50156. More information can be found at https://access.redhat.com/solutions/7073119.

There are several ways to deal with the problem before its resolution:

• Boot the affected system using 8.9 or 9.3 kernels, respectively. See https://access.redhat.com/solutions/226423 for details on booting with a pervious kernel.
• Moving a tape cartridge manually using mtx or sjimm and running 'mt -f <device_handle> rewind' on each in turn may correct the issue appearing after reboot, if NetWorker is unable to access the devices despite them being visible using /proc/scsi/scsi.
• As of 2026-06-18, Red Hat appears to have fixes for version 8.10, 9.4, and 9.6. From the bug record:
  • RHEL8.10: The underlying issues are fixed in kernel-4.18.0-553.42.1.el8_10 (released with RHBA-2025:2352) and later. The fixes were developed in RHEL-78415 and RHEL-28790.
  • RHEL9.4: The underlying issues are fixed in kernel-5.14.0-427.117.1.el9_4 (released with RHSA-2026:6310) and later. The fixes were developed in RHEL-79681 and RHEL-62269.
  • RHEL9.5: Upgrade to a stream where a fix is available.
  • RHEL9.6GA has kernel-5.14.0-570.12.1.el9_6 (released with RHSA-2025:6966), which contains the fixes for this issue. The fixes were developed in RHEL-78429 and RHEL-28791.