SCSI error with Additional Sense Key "Logical unit not ready"

Environment

• Red Hat Enterprise Linux Any Version

Issue

• /var/log/messages reports errors similar to:

  kernel: end_request: I/O error, dev sda, sector 0 
  kernel: Buffer I/O error on device sda, logical block 0 
  kernel: sd 0:0:0:1: Device not ready: <6>: Current: sense key: Not Ready 
  kernel:     Add. Sense: Logical unit not ready, manual intervention required
  

Resolution

Understanding Additional Sense Key "Logical unit not ready"

• This error condition occurs when a request is made of a target and it is not able to respond in any fashion.
• There can be many reasons for this condition, including;
  • Hardware failure
  • Device scans from the operating system
  • Long running tasks already being processed on the device.

Next Actions

• There are some known software causes that exhibit this problem, please review;
  • Cluster node unable to access storage after being fenced with fence_scsi and rebooting in RHEL 6
  • Device not ready errors with EMC Clariion storage but good LVM filters
  • Why does multipathd daemon report failed paths?
  • Why do I see I/O errors on a RHEL system using devices from an active/passive storage array?
• If you are not affected by the conditions in the solutions above, then;
  • Open a Support Case with the hardware vendor
  • If requested by the hardware vendor, open a new Support Case for collaboration with Red Hat, quoting the ticket number from them.

Learn More

SCSI Error Codes Deep Dive

• We have many Solutions explaining SCSI Error Codes that are specific to a combination of Return Code, Sense Key and Hardware.
• We also have an Article that covers SCSI Error codes in depth titled: How do I interpret SCSI status messages in RHEL like "sd 2:0:0:243: SCSI error: return code = 0x08000002"?.

Matching an address to a device

• If you need to further identify a device name from a hardware address, please review How do you map between scsi address <0 0 0 0> (or 0:0:0:0) and scsi device name (sda)?.

This solution has been reviewed for technical accuracy, optimized for search, and integrated with Product Documentation and/or Red Hat Access Labs. Much like when a software package is accepted upstream, this content has moved from the general KCS editing workflow into the responsibility of Customer Content Services as maintainers.