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05459600 BJ |
1 | .TH VMSTAT 1 11/13/79 |
2 | .UC | |
3 | .SH NAME | |
4 | vmstat \- report virtual memory statistics | |
5 | .SH SYNOPSIS | |
6 | .B vmstat | |
7 | [ | |
8 | .B \-fs | |
9 | ] | |
10 | [ interval [ count ] ] | |
11 | .SH DESCRIPTION | |
12 | .I Vmstat | |
13 | delves into the system and reports certain statistics kept about | |
14 | process, virtual memory, disk and cpu activity. | |
15 | If given a | |
16 | .B \-f | |
17 | argument, it reports on the number of | |
18 | .I forks | |
19 | and | |
20 | .I vforks | |
21 | since system startup and the number of pages of virtual memory involved in each | |
22 | kind of fork. | |
23 | If given a | |
24 | .B \-s | |
25 | argument, it prints the contents | |
26 | of the | |
27 | .I sum | |
28 | structure, given the total number of several kinds of paging related | |
29 | events which have occurred since boot. | |
30 | .PP | |
31 | If none of these options are given, | |
32 | .I vmstat | |
33 | will report in a (usually) iterative fashion on the virtual memory | |
34 | activity in the system. | |
35 | In this case, the optional | |
36 | .I interval | |
37 | argument causes | |
38 | .I vmstat | |
39 | to report once each | |
40 | .I interval | |
41 | seconds; | |
42 | ``vmstat 5'' will print what the system is doing every five seconds; | |
43 | this is a good choice of printing interval since this is how often | |
44 | the statistics are sampled in the system. | |
45 | If a | |
46 | .I count | |
47 | is given, the statistics are repeated | |
48 | .I count | |
49 | times. | |
50 | The fields are: | |
51 | .PP | |
52 | Procs: information about numbers of processes in various states. | |
53 | .sp .1i | |
54 | .ta +1i | |
55 | .nf | |
56 | RQ in run queue | |
57 | DW sleeping on short event (disk wait) | |
58 | PW in page wait | |
59 | SL sleeping for short time, and in main memory | |
60 | SW runnable or sleeping for a short time, but swapped out | |
61 | .fi | |
62 | .sp .1i | |
63 | Virtual: information about the state of virtual memory in the system. | |
64 | .sp .1i | |
65 | .ta +1i | |
66 | .nf | |
67 | AVM active virtual pages | |
68 | TX percentage of active pages which were shared text pages | |
69 | .fi | |
70 | .sp .1i | |
71 | Real: information about the state of real memory in the system. | |
72 | .sp .1i | |
73 | .ta +1i | |
74 | .nf | |
75 | USE page frames in use for data+text+stack of active processes | |
76 | TX percentage of USE which is text (shared program) pages | |
77 | FRE size of the free list | |
78 | .fi | |
79 | .sp .1i | |
80 | Fault: information about page faults and paging activity. | |
81 | These are averaged each five seconds, and given in units per second. | |
82 | .sp .1i | |
83 | .ta +1i | |
84 | .nf | |
85 | RE page reclaims (simulating reference bits) | |
86 | PI pages paged in | |
87 | PO dirty page write back rate (pages per second) | |
88 | FR rate at which free list is replenished (pages per second) | |
89 | SR scan rate: pageout daemon rpm (this is in revs/minute) | |
90 | .fi | |
91 | .sp .1i | |
92 | Swp: information about the activity of the swap daemon (process 0). | |
93 | .sp .1i | |
94 | .ta +1i | |
95 | .nf | |
96 | I process swap in rate (processes per 10 seconds) | |
97 | O process swap out rate (processes per 10 seconds) | |
98 | .fi | |
99 | .sp .1i | |
100 | Disk: operations per second (this field is system dependent). | |
101 | .sp .1i | |
102 | .ta +1i | |
103 | .nf | |
104 | RP /usr (user) file transactions and root file activity | |
105 | RM paging and /tmp (temporary) file activity | |
106 | .fi | |
107 | .sp .1i | |
108 | Cpu: cpu context switch rate and breakdown of cpu | |
109 | usage by percentage in last few seconds. | |
110 | .sp .1i | |
111 | .ta +1i | |
112 | .nf | |
113 | CS cpu context switch rate in switches per second | |
114 | .sp .1i | |
115 | US user time | |
116 | SY system time | |
117 | ID cpu idle | |
118 | .fi | |
119 | .PP | |
120 | Any time not accounted for by US+SY+ID is given to low priority jobs. | |
121 | .SH FILES | |
122 | /dev/kmem, /vmunix | |
123 | .SH SEE ALSO | |
124 | The section on configuration in | |
125 | .I "Setting up the Virtual Memory Extensions to the UNIX System" | |
126 | by O. Babaoglu and W. Joy | |
127 | .SH AUTHORS | |
128 | William Joy and Ozalp Babaoglu | |
129 | .SH BUGS | |
130 | So many numbers print out that its sometimes hard to figure out what to watch. |