bcc-bitesize(8)
| bitesize(8) | System Manager's Manual | bitesize(8) |
NAME
bitesize - Summarize block device I/O size as a histogram - Linux eBPF/bcc.
SYNOPSIS
bitesize
DESCRIPTION
Show I/O distribution for requested block sizes, by process name.
This works by tracing block:block_rq_issue and prints a histogram of I/O size.
Since this uses BPF, only the root user can use this tool.
REQUIREMENTS
CONFIG_BPF and bcc.
EXAMPLES
- Count I/O size per process until Ctrl-C is hit:
- # bitesize
FIELDS
- Kbtes
- Size in kilobytes of range
- count
- How many I/O fell into this range
- distribution
- An ASCII bar chart to visualize the distribution (count column)
OVERHEAD
This traces a block I/O tracepoint to update a histogram, which is asynchronously copied to user-space. This method is very efficient, and the overhead for most storage I/O rates (< 10k IOPS) should be negligible. If you have a higher IOPS storage environment, test and quantify the overhead 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
Allan McAleavy
SEE ALSO
https://github.com/brendangregg/systemtap-lwtools/blob/master/disk/bitesize-nd.stp
| 2016-02-05 | USER COMMANDS |
