1SADC(8) Linux User's Manual SADC(8)
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6 sadc - System activity data collector.
7
9 /usr/lib64/sa/sadc [ -C comment ] [ -D ] [ -F ] [ -L ] [ -V ] [ -S {
10 DISK | INT | IPV6 | POWER | SNMP | XDISK | ALL | XALL [,...] } ] [
11 interval [ count ] ] [ outfile ]
12
14 The sadc command samples system data a specified number of times
15 (count) at a specified interval measured in seconds (interval). It
16 writes in binary format to the specified outfile or to standard output.
17 If outfile is set to -, then sadc uses the standard system activity
18 daily data file (see below). In this case, if the file already exists,
19 sadc will overwrite it if it is from a previous month. By default sadc
20 collects most of the data available from the kernel. But there are
21 also optional metrics, for which the relevant options must be explic‐
22 itly passed to sadc to be collected (see option -S below).
23 The standard system activity daily data file is named saDD unless
25 option -D is used, in which case its name is saYYYYMMDD, where YYYY
26 stands for the current year, MM for the current month and DD for the
27 current day. By default it is located in the /var/log/sa directory.
28 Yet it is possible to specify an alternate location for it: If outfile
29 is a directory (instead of a plain file) then it will be considered as
30 the directory where the standard system activity daily data file will
31 be saved.
32 When the count parameter is not specified, sadc writes its data end‐
34 lessly. When both interval and count are not specified, and option -C
35 is not used, a dummy record, which is used at system startup to mark
36 the time when the counter restarts from 0, will be written. For exam‐
37 ple, one of the system startup script may write the restart mark to the
38 daily data file by the command entry:
39 /usr/lib64/sa/sadc -
41 The sadc command is intended to be used as a backend to the sar com‐
43 mand.
44 Note: The sadc command only reports on local activities.
46
49 -C comment
50 When neither the interval nor the count parameters are speci‐
51 fied, this option tells sadc to write a dummy record containing
52 the specified comment string. This comment can then be dis‐
53 played with option -C of sar.
54 -D Use saYYYYMMDD instead of saDD as the standard system activity
56 daily data file name.
57 -F The creation of outfile will be forced. If the file already
59 exists and has a format unknown to sadc then it will be trun‐
60 cated. This may be useful for daily data files created by an
61 older version of sadc and whose format is no longer compatible
62 with current one.
63 -L sadc will try to get an exclusive lock on the outfile before
65 writing to it or truncating it. Failure to get the lock is
66 fatal, except in the case of trying to write a normal (i.e. not
67 a dummy and not a header) record to an existing file, in which
68 case sadc will try again at the next interval. Usually, the only
69 reason a lock would fail would be if another sadc process were
70 also writing to the file. This can happen when cron is used to
71 launch sadc. If the system is under heavy load, an old sadc
72 might still be running when cron starts a new one. Without lock‐
73 ing, this situation can result in a corrupted system activity
74 file.
75 -S { DISK | INT | IPV6 | POWER | SNMP | XDISK | ALL | XALL [,...] }
77 Specify which optional activities should be collected by sadc.
78 Some activities are optional to prevent data files from growing
79 too large. The DISK keyword indicates that sadc should collect
80 data for block devices. The INT keyword indicates that sadc
81 should collect data for system interrupts. The IPV6 keyword
82 indicates that IPv6 statistics should be collected by sadc. The
83 POWER keyword indicates that sadc should collect power manage‐
84 ment statistics. The SNMP keyword indicates that SNMP statis‐
85 tics should be collected by sadc. The ALL keyword is equivalent
86 to specifying all the keywords above and therefore all previous
87 activities are collected.
88 The XDISK keyword is an extension to the DISK one and indicates
90 that partitions and filesystems statistics should be collected
91 by sadc in addition to disk statistics. This option works only
92 with kernels 2.6.25 and later. The XALL keyword is equivalent
93 to specifying all the keywords above (including keyword exten‐
94 sions) and therefore all possible activities are collected.
95 Important note: The activities (including optional ones) saved
97 in an existing data file prevail over those selected with option
98 -S. As a consequence, appending data to an existing data file
99 will result in option -S being ignored.
100 -V Print version number then exit.
102
105 The sadc command takes into account the following environment variable:
106 S_TIME_DEF_TIME
109 If this variable exists and its value is UTC then sadc will save
110 its data in UTC time. sadc will also use UTC time instead of
111 local time to determine the current daily data file located in
112 the /var/log/sa directory.
113
115 /usr/lib64/sa/sadc 1 10 /tmp/datafile
116 Write 10 records of one second intervals to the /tmp/datafile
117 binary file.
118 /usr/lib64/sa/sadc -C Backup_Start /tmp/datafile
120 Insert the comment Backup_Start into the file /tmp/datafile.
121
123 The /proc filesystem must be mounted for the sadc command to work.
124 All the statistics are not necessarily available, depending on the ker‐
126 nel version used. sadc assumes that you are using at least a 2.6 ker‐
127 nel.
128
130 /var/log/sa/saDD
131 /var/log/sa/saYYYYMMDD
132 The standard system activity daily data files and their default
133 location. YYYY stands for the current year, MM for the current
134 month and DD for the current day.
135 /proc and /sys contain various files with system statistics.
137
139 Sebastien Godard (sysstat <at> orange.fr)
140
142 sar(1), sa1(8), sa2(8), sadf(1), sysstat(5)
143 http://pagesperso-orange.fr/sebastien.godard/
145Linux DECEMBER 2016 SADC(8)