71-2
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
 
Chapter 71      Onboard Failure Logging (OBFL)
Restrictions for OBFL
Restrictions for OBFL
They include:
• Software Restrictions—If a device (router or switch) intends to use linear flash memory as its OBFL 
storage media, Cisco IOS software must reserve a minimum of two physical sectors (or physical 
blocks) for the OBFL feature. Because an erase operation for a linear flash device is done on 
per-sector (or per-block) basis, one extra physical sector is needed. Otherwise, the minimum amount 
of space reserved for the OBFL feature on any device must be at least 8 KB.
• Firmware Restrictions—If a line card or port adapter runs an operating system or firmware that is 
different from the Cisco IOS operating system, the line card or port adapter must provide device 
driver level support or an interprocess communications (IPC) layer that allows the OBFL file system 
to communicate to the line card or port adapter. This requirement is enforced to allow OBFL data to 
be recorded on a storage device attached to the line card or port adapter.
• Hardware Restrictions—To support the OBFL feature, a device must have at least 8 KB of 
nonvolatile memory space reserved for OBFL data logging.
Information About OBFL
• Overview of OBFL, page 71-2
• Information about Data Collected by OBFL, page 71-2
Overview of OBFL 
The Onboard Failure Logging (OBFL) feature collects data such as operating temperatures, hardware 
uptime, interrupts, and other important events and messages from system hardware installed in a Cisco 
router or switch. The data is stored in nonvolatile memory and helps technical personnel diagnose 
hardware problems.
Information about Data Collected by OBFL 
• OBFL Data Overview, page 71-2
• Temperature, page 71-3
• Operational Uptime, page 71-4
• Interrupts, page 71-6
• Message Logging, page 71-7
OBFL Data Overview
The OBFL feature records operating temperatures, hardware uptime, interrupts, and other important 
events and messages that can assist with diagnosing problems with hardware cards (or modules) installed 
in a Cisco router or switch. Data is logged to files stored in nonvolatile memory. When the onboard 
hardware is started up, a first record is made for each area monitored and becomes a base value for 
subsequent records. The OBFL feature provides a circular updating scheme for collecting continuous 
records and archiving older (historical) records, ensuring accurate data about the system. Data is