Disk IO Specification

Linux Disk Trace Buffer Format

Each trace record contains sixteen (16) bytes of information in the following format:

version 1.1 (added SCSI support)

Byte	Content	Value
1	read/write	'r'/'w'
2	device major number/write	0-255
3	device minor number	0-255
4	LBA/CHS/SCSI	'L'/'C'/'S'
5-8	number of sectors requested	unsigned long
9-12	sector / block number	unsigned long
13-16	time of request (in jiffies)	unsigned long

• dtbprinter is a simple C program that prints the disk trace.
• dtb.h is the include file that goes with it.
• If you get unusually large numbers for the unsigned long values, you might have an endian problem.

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version 1.0 (IDE only)

Byte	Content	Value
1	read/write	'r'/'w'
2	device major number/write	0-255
3	device minor number	0-255
4	LBA/CHS	'L'/'C'
5-8	number of sectors requested	unsigned long
9-12	sector / block number	unsigned long
13-16	time of request (in jiffies)	unsigned long