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bitesize(8) | System Manager's Manual | bitesize(8) |
NAME¶
bitesize - Summarize block device I/O size as a histogram - Linux eBPF/bcc.SYNOPSIS¶
bitesizeDESCRIPTION¶
Show I/O distribution for requested block sizes, by process name.This works by tracing block I/O kernel functions using dynamic tracing and prints a historgram 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 kernel block I/O functions to update a histgroam, which are 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.Also look in the bcc distribution for a companion _examples.txt file containing example usage, output, and commentary for this tool.
OS¶
LinuxSTABILITY¶
Unstable - in development.AUTHOR¶
Allan McAleavySEE ALSO¶
https://github.com/brendangregg/systemtap-lwtools/blob/master/disk/bitesize-nd.stp2016-02-05 | USER COMMANDS |