bcc-biopattern - Man Page
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.
Show help message and exit.
Trace this disk only.
Print output every interval seconds, if any.
Number of interval summaries.
- Trace access patterns of all disks, and print a summary on Ctrl-C:
- Trace disk sdb only:
# biopattern -d sdb
- Print 1 second summaries, 10 times:
# biopattern 1 10
Time of the output, in HH:MM:SS format.
Disk device name.
Ratio of random I/O.
Ratio of sequential I/O.
Number of I/O during the interval.
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.
Also look in the bcc distribution for a companion _examples.txt file containing example usage, output, and commentary for this tool.
Unstable - in development.
biosnoop(8), biolatency(8), iostat(1)