79 lines
1.7 KiB
Groff
79 lines
1.7 KiB
Groff
.TH biopattern 8 "2022-02-21" "USER COMMANDS"
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.SH NAME
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biopattern \- Identify random/sequential disk access patterns.
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.SH SYNOPSIS
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.B biopattern [\-h] [\-d DISK] [interval] [count]
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.SH DESCRIPTION
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This traces block device I/O (disk I/O), and prints ratio of random/sequential I/O
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for each disk or the specified disk either on Ctrl-C, or after a given interval in seconds.
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This works by tracing kernel tracepoint block:block_rq_complete.
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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 OPTIONS
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.TP
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\-h
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Show help message and exit.
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.TP
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\-d
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Trace this disk only.
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.TP
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interval
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Print output every interval seconds, if any.
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.TP
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count
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Number of interval summaries.
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.SH EXAMPLES
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.TP
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Trace access patterns of all disks, and print a summary on Ctrl-C:
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#
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.B biopattern
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.TP
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Trace disk sdb only:
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#
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.B biopattern -d sdb
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.TP
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Print 1 second summaries, 10 times:
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#
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.B biopattern 1 10
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.SH FIELDS
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.TP
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TIME
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Time of the output, in HH:MM:SS format.
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.TP
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DISK
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Disk device name.
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.TP
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%RND
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Ratio of random I/O.
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.TP
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%SEQ
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Ratio of sequential I/O.
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.TP
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COUNT
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Number of I/O during the interval.
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.TP
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KBYTES
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Total Kbytes for these I/O, during the interval.
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.SH OVERHEAD
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Since block device I/O usually has a relatively low frequency (< 10,000/s),
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the overhead for this tool is expected to be low or negligible. For high IOPS
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storage systems, test and quantify 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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Rocky Xing
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.SH SEE ALSO
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biosnoop(8), biolatency(8), iostat(1)
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