netbsd-tips revision 1.13 1 List 20 largest files (larger than 5 MB) sorted by megabytes:
2
3 find / -type f -size +10000 -print0 | xargs -0 du -m | sort -nr | head -20
4 %
5 You can keep specific rc.conf configurations in individual files
6 under /etc/rc.conf.d/ where each file is named after the $name of
7 the rc.d script. Some configurations may have different names than
8 the script; see the $name variable to check.
9 %
10 You can see the total used buffers in megabytes with:
11
12 vmstat -s | awk '
13 / bytes per page$/ { bpp = $1 }
14 / cached file pages$/ { cfp = $1 }
15 / cached executable pages$/ { cep = $1 }
16 END { print((cfp + cep) * bpp / 1024 / 1024); }'
17 %
18 You can view a value of a variable in pkgsrc by using the show-var
19 target, for example:
20
21 make show-var VARNAME=MAINTAINER
22 %
23 You can view the basic order of your rc.d scripts with:
24
25 rcorder /etc/rc.d/*
26 %
27 You can ask questions about NetBSD at the netbsd-users (a] NetBSD.org
28 mailing list. Be sure to clearly explain your problem, what you
29 tried, what results you had, and what you expected.
30 %
31 You can view your non-default Postfix settings with:
32
33 postconf -n
34 %
35 To report about installed packages with known vulnerabilities,
36 fetch the latest pkg-vulnerabilities file as the superuser with:
37
38 pkg_admin fetch-pkg-vulnerabilities
39
40 And then run:
41
42 pkg_admin audit
43 %
44 The following shows an example of temporarily adding 10MB more swap
45 space for virtual memory:
46
47 dd if=/dev/zero of=/root/swapfile bs=1024 count=10240
48 chmod go= /root/swapfile
49 swapctl -a /root/swapfile
50 %
51 If your console ever gets broken, you can try resetting it to its
52 initial state with:
53
54 printf "\033c"
55 %
56 If you installed a package, but don't know what the software is
57 called or what executables to run, use pkg_info with the -L switch
58 to list the package's files and search for /bin:
59
60 pkg_info -L PACKAGE-NAME | grep /bin
61 %
62 A new user can be added by using the useradd tool with the -m switch
63 to create the home directory. Then set the password. For example:
64
65 useradd -m susan
66 passwd susan
67 %
68 To modify user account information use the chpass or usermod tools.
69 If you need to edit the user database directly, use the vipw command.
70 %
71 You can temporarily start the SSH server by running the following
72 as root:
73
74 /etc/rc.d/sshd onestart
75 %
76 Several NPF examples are available in the /usr/share/examples/npf/
77 directory.
78 %
79 Want to dual boot using a bluetooth mouse or keyboard? Use btkey(1)
80 to store the link key in the hardware.
81 %
82 If you are having trouble connecting to a remote bluetooth device,
83 try the btconfig(8) inquiry command. The kernel will retain some
84 clock offset information that may help.
85 %
86 You can download files via HTTP using the ftp(1) command; for example:
87
88 ftp http://www.NetBSD.org/images/NetBSD.png
89 %
90 The mtree(8) tool can be used to check permissions, ownerships,
91 file changes, and more when compared against a specification. For
92 example to check directory ownership and permissions for standard
93 NetBSD directories, run:
94
95 /usr/sbin/mtree -e -p / -f /etc/mtree/NetBSD.dist
96 %
97 If you need reminders on your console to leave, use the leave(1)
98 tool. For example to receive reminders to leave in one hour:
99
100 leave +0100
101 %
102 To stop non-superuser logins until next boot, as root:
103
104 touch /etc/nologin
105 %
106 When extracting distribution tar sets, be sure to use the pax -pe
107 option or the tar -p switch to preserve the user and group and file
108 modes (including setuid and setgid). This is needed, for example,
109 so su(1) will work after extracting the base.tgz set.
110 %
111 Math can be done within the sh(1) and ksh(1) shells or with expr(1),
112 dc(1), bc(1), or awk(1). Here are some simple examples:
113
114 echo $((431 * 79))
115 expr 60 \* 60 \* 24 \* 7
116 %
117 You can view network connections with the fstat, netstat -a, sockstat,
118 and "systat netstat" commands.
119 %
120 Visit the NetBSD Security website to keep track of advisories:
121 http://www.NetBSD.org/support/security/
122 Or join the security-announce mailing list for alerts:
123 http://www.NetBSD.org/mailinglists/#security-announce
124 %
125 Here's an example of finding what package a file belongs to:
126
127 pkg_info -Fe /usr/pkg/bin/inw
128 %
129 Many log files are checked for rotation every hour by newsyslog(8).
130 It is configured in /etc/newsyslog.conf.
131 %
132 NetBSD's default cron jobs are defined in the /var/cron/tabs/root
133 file. As the superuser, use "crontab -l" to view it. To edit it,
134 use "crontab -e" (which defaults to using the vi(1) editor).
135 %
136 You can make sure that your system is stable and behaves correctly by
137 running the tests in /usr/tests (which come from the tests.tgz set).
138 To do so:
139
140 vi /etc/atf/NetBSD.conf
141 cd /usr/tests
142 atf-run | atf-report
143 %
144 To share files from your NetBSD system, you can use the built-in
145 httpd(8). Uncomment the 'http' lines in /etc/inetd.conf, reload inetd
146 with service(8), and then any files in /var/www will be published to
147 http://127.0.0.1/.
148 %
149 You can schedule simple periodic tasks for your NetBSD system to run
150 without using cron(8) by editing the sh(1) scripts /etc/daily.local,
151 /etc/weekly.local, and /etc/monthly.local.
152 %
153 NetBSD's tar(1) command can handle a wide range of file types, e.g.
154 zip, 7z, and rar, and will autodetect the type of the file based
155 on its extension. For example, to extract a zip file:
156
157 tar xvf example.zip
158 %
159 You can use progress(1) to monitor the progress of data in a pipe:
160
161 zcat example.tar.gz | progress tar xf -
162 %
163 Press CTRL+T to send SIGINFO and see the current status of the
164 command running in the current terminal.
165 %
166 To enable the Multicast DNS responder, add
167
168 mdnsd=YES
169
170 to /etc/rc.conf. Your system will now be reachable on the network as
171 hostname.local.
172
173 To enable Multicast DNS lookups, add mdnsd to the 'hosts' field in
174 /etc/nsswitch.conf.
175 %
176 NetBSD includes a tutorial on using vi(1), the classic BSD text
177 editor:
178
179 less /usr/share/doc/usd/vi/vitut.txt
180 %
181 A login shell will read initial commands from ~/.profile.
182
183 When using the X Window System, initializing with 'startx' will
184 read ~/.xinitrc. Initializing with xdm will read commands from
185 ~/.xsession, but logins through xdm will not read ~/.profile.
186 %
187 After installing NetBSD, additional sets can be installed with
188 sysinst(8).
189 %
190 Depending on the version of NetBSD, the system may raise the sysctl(8)
191 variable kern.securelevel to 1 on boot. The system's securelevel may be
192 raised by the superuser, but never lowered.
193
194 To learn more about the different securelevel settings, see:
195
196 man secmodel_securelevel
197 %
198 To learn more about the various security features in NetBSD, see:
199
200 man 7 security
201 %
202 Network interface traffic can be monitored with the following
203 command:
204
205 sysstat ifstat
206 %
207 To list connected disk devices:
208
209 sysctl hw.disknames
210