vmstat - report virtual memory statistics
vmstat [-ikpqQsSw] [-T u | d] [disks] [interval [count] [start_time]]
vmstat reports virtual memory statistics regarding kernel thread, virtual memory, disk, trap, and CPU activity.
On MP (multi-processor) systems, vmstat averages the number of CPUs into the output. For per-processor statistics, see mpstat(8).
vmstat only supports statistics for certain devices. For more general system statistics, use sar(1), iostat(8), or sar(8).
Without options, vmstat displays a one-line summary of the virtual memory activity since the system was booted.
During execution of the kernel status command, the state of the system can change. If relevant, a state change message is included in the vmstat output, in one of the following forms:
<<device added: sd0>> <<device removed: sd0>> <<processors added: 1, 3>> <<processors removed: 1, 3>>
The following options are supported:
Report the number of interrupts per device. count and interval does not apply to the –i option.
Report paging activity in details. This option will display the following, respectively:
Executable page-ins.
Executable page-outs.
Executable page-frees.
Anonymous page-ins.
Anonymous page-outs.
Anonymous page-frees.
File system page-ins.
File system page-outs.
File system page-frees.
When executed in a zone and if the pools facility is active, all of the above only report activity on the processors in the processor set of the zone's pool.
Suppress messages related to state changes.
Do not print historical information as 1st line of output.
Display the total number of various system events since boot. count and interval does not apply to the –s option.
Report on swapping rather than paging activity. This option will change two fields in vmstat's paging display: rather than the ‘re’ and ‘mf’ fields, vmstat will report ‘si’ (swap-ins) and ‘so’ (swap-outs).
Specify u for a printed representation of the internal representation of time. See time(2). Specify d for standard date format. See date(1).
Wide display format. Headers will be more descriptive and two space gap is provided between each column.
Refer the examples section for sample outputs
Fall back to use the kstat(8) interfaces as the source of data. By default, the source of data is sstored(8)
The following operands are supported:
Displays count operand reports only. Note that the count operand does not apply to the –i and –s options.
Specifies which disks are to be given priority in the output (only four disks fit on a line). Common disk names are id, sd, xd, or xy, followed by a number (for example, sd2, xd0, and so forth).
Reports each interval seconds. Note that interval operand does not apply to the –i and –s options.
Specifies the time at which to start querying the statistics. If available, sstored(8) queries historical statistics. The time operand accepts ISO8601 extended (%Y-%m-%dT%H:%M:%S) formatted times, specifically the UTC or local time forms. For example:
2021-07-14T17:06:09Z (UTC time) 2015-07-14T16:06:09 (assumed to be local time)
When you specify the start_time operand, you must also specify the interval and count operands.
Note that the start_time does not apply to the –i, –s, and –k options.
The following command displays a summary of what the system is doing every five seconds.
example% vmstat 5 kthr memory page disk faults cpu r b w swap free re mf pi p fr de sr s0 s1 s2 s3 in sy cs us sy id 0 0 0 11456 4120 1 41 19 1 3 0 2 0 4 0 0 48 112 130 4 14 82 0 0 1 10132 4280 0 4 44 0 0 0 0 0 23 0 0 211 230 144 3 35 62 0 0 1 10132 4616 0 0 20 0 0 0 0 0 19 0 0 150 172 146 3 33 64 0 0 1 10132 5292 0 0 9 0 0 0 0 0 21 0 0 165 105 130 1 21 78 1 1 1 10132 5496 0 0 5 0 0 0 0 0 23 0 0 183 92 134 1 20 79 1 0 1 10132 5564 0 0 25 0 0 0 0 0 18 0 0 131 231 116 4 34 62 1 0 1 10124 5412 0 0 37 0 0 0 0 0 22 0 0 166 179 118 1 33 67 1 0 1 10124 5236 0 0 24 0 0 0 0 0 14 0 0 109 243 113 4 56 39 ^C example%
The fields of vmstat's display are
Report the number of kernel threads in each of the three following states:
the number of kernel threads in run queue
the number of blocked kernel threads that are waiting for resources I/O, paging, and so forth
the number of swapped out lightweight processes (LWPs) that are waiting for processing resources to finish.
Report on usage of virtual and real memory.
available swap space (Kbytes)
size of the free list (Kbytes)
Report information about page faults and paging activity. The information on each of the following activities is given in units per second.
page reclaims — but see the –S option for how this field is modified.
minor faults — but see the –S option for how this field is modified.
kilobytes paged in
kilobytes paged out
kilobytes freed
anticipated short-term memory shortfall (Kbytes)
pages scanned by clock algorithm
When executed in a zone and if the pools facility is active, all of the above (except for ‘de’) only report activity on the processors in the processor set of the zone's pool.
Report the number of disk operations per second. There are slots for up to four disks, labeled with a single letter and number. The letter indicates the type of disk (s = SCSI, i = IPI, and so forth); the number is the logical unit number.
Report the trap/interrupt rates (per second).
interrupts
system calls
CPU context switches
When executed in a zone and if the pools facility is active, all of the above only report activity on the processors in the processor set of the zone's pool.
Give a breakdown of percentage usage of CPU time. On MP systems, this is an average across all processors.
user time
system time
idle time
When executed in a zone and if the pools facility is active, all of the above only report activity on the processors in the processor set of the zone's pool.
example% vmstat -w Kernel_Threads Virtual_Memory Paging_Info Disk_Ops/s Faults_per_sec CPU_Usage Run Block Wait Swap(KBs) Free(KBs) Reclaim MinorFault PageIn PageOut Freed Def Scan s0 s1 s2 s3 Intr Syscal CPU_Sw User% Sys% Idle% Time 15 0 0 118713700 56911268 16274 141727 14 0 0 0 0 38 38 33 33 9496 129607 5687 21 8 72 Wed Dec 16 21:59:26 PST 2020Example 3 vmstat wide display sample-2
example% vmstat -Sw Kernel_Threads Virtual_Memory Paging_Info Disk_Ops/s Faults_per_sec CPU_Usage Run Block Wait Swap(KBs) Free(KBs) SwapIn SwapOut PageIn PageOut Freed Def Scan s0 s1 s2 s3 Intr Syscal CPU_Sw User% Sys% Idle% Time 15 0 0 118714260 56911844 0 0 14 0 0 0 0 38 38 33 33 9496 129608 5687 21 8 72 Wed Dec 16 21:59:24 PST 2020Example 4 vmstat wide display sample-3
example% vmstat -wp
Virtual_Memory Paging_Info Executable Anonymous_Pages Filesystem
Swap(KBs) Free(KBs) Reclaim MinorFault Freed Def Scan PageIn PageOut PageFree PageIn PageOut PageFree PageIn PageOut PageFree Time
114023436 52311932 17876 156365 0 0 0 0 0 0 3 0 0 10 0 0 Thu Dec 17 03:04:51 PST 2020
Example 5 vmstat viewing historical data
The following example shows how to create a report that contains historical statistics since 2021-September-27 06:11:04+05:30. The statistics are output every second for ten times.
example% vmstat 1 10 2021-09-27T6:11:04+5:30
kthr memory page disk faults cpu
r b w swap free re mf pi po fr de sr vc -- -- -- in sy cs us sy id
0 0 0 3226613 1208475 1 1 0 0 0 0 0 0 0 0 0 464 87 382 0 0 100
0 0 0 3602720 1587608 0 0 0 0 0 0 0 0 0 0 0 518 304 464 0 0 100
2 0 0 3602720 1587608 0 0 0 0 0 0 0 0 0 0 0 485 305 400 0 0 100
0 0 0 3602720 1587608 0 0 0 0 0 0 0 0 0 0 0 510 307 384 0 0 100
0 0 0 3602720 1587608 0 0 0 0 0 0 0 0 0 0 0 501 306 420 0 0 100
1 0 0 3602720 1587608 0 0 0 0 0 0 0 0 0 0 0 522 317 433 0 0 99
1 0 0 3602720 1587608 0 0 0 0 0 0 0 0 0 0 0 511 311 412 0 0 100
0 0 0 3602720 1587608 0 0 0 0 0 0 0 0 0 0 0 471 303 382 0 0 100
1 0 0 3602720 1587608 0 0 0 0 0 0 0 0 0 0 0 502 308 413 0 0 100
0 0 0 3602720 1587608 0 0 0 0 0 0 0 0 0 0 0 470 302 396 0 0 100
See attributes(7) for descriptions of the following attributes:
|
Invocation is evolving. Human readable output is unstable.
date(1), sar(1), time(2), attributes(7), iostat(8), mpstat(8), sar(8)
The sum of CPU utilization might vary slightly from 100 because of rounding errors in the production of a percentage figure.
On some virtualized systems, such as a kernel zone (see solaris-kz(7)), the sum of CPU utilization reported may be below 100 due to CPU time stolen by the host system. The mpstat(8) command can be used to report stolen time.
In order to view historical data via vmstat, the sstore collection vm-stats must have been enabled for the time period being observed. Refer to sstoreadm(1) for more information about enabling a sstore collection.