Instance Fails to Start/Power On: "blockdev: cannot open /dev/XXX: No such device or address"

Problem

Instance fails to start or be powered on and transitions into an ERROR state with the following fault/error message: "blockdev: cannot open /dev/XXX: No such device or address".

Environment

  • Platform9 Managed OpenStack - All Versions
  • Cinder (Block Storage)
  • LVM
  • iSCSI

Cause

A stale iSCSI target/connection – one that has not been logged out promptly following the shutdown of the VM – is present and the connection information is no longer valid.

Resolution

1) Identify which iSCSI target corresponds to the unknown device (i.e. /dev/XXX).

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2) Logout the iSCSI target.

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3) Restart or start the Instance/VM.

The 'attached scsi disk' will be followed by the device name without the preceding /dev path. For example, in the output above, the corresponding device name is sdcd.

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