hotspot.d(1m)

hotspot.d1m

Print disk event by location. uses dtrace.

Usage

hotspot.d

Overview

hotspot.d is a simple DTrace script to determine if disk activity is occuring in the one place - a "hotspot". This helps us understand the system's usage of a disk, it does not imply that the existance or not of a hotspot is good or bad (often may be good, less seeking).

Since this uses DTrace, only users with root privileges can run this command.

Examples

Sample until Ctrl-C is hit then print report,

# hotspot.d

Fields

Disk

disk instance name

Major

driver major number

Minor

driver minor number

value

location of disk event, megabytes

count

number of events

Documentation

See the DTraceToolkit for further documentation under the Docs directory. The DTraceToolkit docs may include full worked examples with verbose descriptions explaining the output.

Exit

hotspot.d will sample until Ctrl-C is hit.

Releases

115 releases since Mac OS X 10.5; the text changed 1 time.

  1. 10.5–10.5.8
  2. 10.6–26.5

Author

Brendan Gregg [Sydney, Australia]

From dtrace 413 in macOS 26.5. Parsed by carta from the page's man source.