NAME

hotspot.d - print disk event by location. Uses DTrace.

SYNOPSIS

hotspot.d

DESCRIPTION

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.

AUTHOR

Brendan Gregg [Sydney, Australia]