Section 8 · System administration

bcc-biopattern.8

Package: bcc-tools

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biopattern

NAME
SYNOPSIS
DESCRIPTION
REQUIREMENTS
OPTIONS
EXAMPLES
FIELDS
OVERHEAD
SOURCE
OS
STABILITY
AUTHOR
SEE ALSO

NAME

biopattern − Identify random/sequential disk access patterns.

SYNOPSIS

biopattern [−h] [−d DISK] [interval] [count]

DESCRIPTION

This traces block device I/O (disk I/O), and prints ratio of random/sequential I/O for each disk or the specified disk either on Ctrl-C, or after a given interval in seconds.

This works by tracing kernel tracepoint block:block_rq_complete.

Since this uses BPF, only the root user can use this tool.

REQUIREMENTS

CONFIG_BPF and bcc.

OPTIONS


	−h		Show help message and exit.
	−d		Trace this disk only.

interval

Print output every interval seconds, if any.


	count		Number of interval summaries.

EXAMPLES

Trace access patterns of all disks, and print a summary on Ctrl-C:

biopattern

Trace disk sdb only:

biopattern -d sdb

Print 1 second summaries, 10 times:

biopattern 1 10

FIELDS


	TIME		Time of the output, in HH:MM:SS format.
	DISK		Disk device name.
	%RND		Ratio of random I/O.
	%SEQ		Ratio of sequential I/O.
	COUNT		Number of I/O during the interval.
	KBYTES		Total Kbytes for these I/O, during the interval.

OVERHEAD

Since block device I/O usually has a relatively low frequency (< 10,000/s), the overhead for this tool is expected to be low or negligible. For high IOPS storage systems, test and quantify before use.

SOURCE

This is from bcc.

https://github.com/iovisor/bcc

Also look in the bcc distribution for a companion _examples.txt file containing example usage, output, and commentary for this tool.

OS

Linux

STABILITY

Unstable - in development.

AUTHOR

Rocky Xing