biopattern(8)

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

SEE ALSO
biosnoop(8), biolatency(8), iostat(1)