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How to use DTrace and mdb to Interpret vmstat Statistics (Doc ID 1009494.1)

Last updated on JUNE 22, 2020

Applies to:

Solaris Operating System - Version 10 3/05 and later
All Platforms


Vmstat reports system-wide physical and virtual memory (swap) usage and CPU utilization.  Vmstat statistics can be used to estimate:

The purpose of this document is to interpret vmstat statistics and demonstrate how advanced tools like DTrace and mdb can be used to drill down into vmstat statistics for evaluating overall system performance.

It's preferable to have the DTraceToolkit on the target system. It contains a collection of over 200 useful and documented DTrace scripts developed by Brendan Gregg.

Sample output:


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In this Document
 kthr: Runnable Threads (r)
 kthr: Block Threads (b)
 kthr: Swapped out Threads (w)
 memory: Available virtual swap (swap)
 memory: Available physical memory (free)
 page: Pages reclaimed (re)
 page: Minor faults (mf)
 page: Kilobytes paged in (pi)
 page: Kilobytes paged out (po)
 page: Kilobytes freed by page scanner (fr)
 page: Anticipated memory shortfall (de)
 page: Number of Pages scanned by page scanner (sr)
 disk: disk operation per second (m0,1,2,3)
 faults: Number of interrupts serviced by CPUs (in)
 faults: Number of system calls issued (sy)
 faults: Context switching activity (cs)
 cpu: user or application CPU time (us)
 cpu: Kernel CPU usage (sy)
 cpu: CPU idle  (id)

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