biopattern - Identify random/sequential disk access patterns. biopattern [-h] [-d DISK] [interval] [count] 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. CONFIG_BPF and bcc.

-h Show help message and exit.

-d Trace this disk only.

interval Print output every interval seconds, if any.

count Number of interval summaries.

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

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.

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. 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.

Linux Unstable - in development. Rocky Xing biosnoop(8), biolatency(8), iostat(1)