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