52 lines
1.3 KiB
Groff
52 lines
1.3 KiB
Groff
.TH bitesize 8 "2016-02-05" "USER COMMANDS"
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.SH NAME
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bitesize \- Summarize block device I/O size as a histogram \- Linux eBPF/bcc.
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.SH SYNOPSIS
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.B bitesize
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.SH DESCRIPTION
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Show I/O distribution for requested block sizes, by process name.
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This works by tracing block:block_rq_issue and prints a historgram of I/O size.
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Since this uses BPF, only the root user can use this tool.
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.SH REQUIREMENTS
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CONFIG_BPF and bcc.
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.SH EXAMPLES
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.TP
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Count I/O size per process until Ctrl-C is hit:
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#
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.B bitesize
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.SH FIELDS
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.TP
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Kbtes
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Size in kilobytes of range
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.TP
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count
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How many I/O fell into this range
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.TP
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distribution
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An ASCII bar chart to visualize the distribution (count column)
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.SH OVERHEAD
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This traces a block I/O tracepoint to update a histogram, which is
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asynchronously copied to user-space. This method is very efficient, and
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the overhead for most storage I/O rates (< 10k IOPS) should be negligible.
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If you have a higher IOPS storage environment, test and quantify the overhead
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before use.
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.SH SOURCE
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This is from bcc.
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.IP
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https://github.com/iovisor/bcc
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.PP
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Also look in the bcc distribution for a companion _examples.txt file containing
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example usage, output, and commentary for this tool.
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.SH OS
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Linux
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.SH STABILITY
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Unstable - in development.
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.SH AUTHOR
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Allan McAleavy
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.SH SEE ALSO
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https://github.com/brendangregg/systemtap-lwtools/blob/master/disk/bitesize-nd.stp
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