1: This is the NetBSD System Manager's Manual, derived from the [bsdwiki book](http://bsdwiki.reedmedia.net/).
2:
3: **Contents**
4:
5: [[!toc levels=3]]
6:
7: # Installing and Upgrading NetBSD
8:
9: ## Recognize the installation program used by NetBSD
10:
11: ## Recognize which commands are available for upgrading
12:
13: ## Understand the difference between a pre-compiled binary and compiling from source
14:
15: ## Understand when it is preferable to install a pre-compiled binary and how to do so
16:
17: if cpu power is low and or disk space is limited.
18:
19: ## Recognize the available methods for compiling a customized binary
20:
21: ## Determine what software is installed on a system
22:
23: To obtain a list of all third-party software installed on a NetBSD system using the [pkgsrc](http://www.pkgsrc.org) package management system, execute the [pkg_info(1)](http://netbsd.gw.com/cgi-bin/man-cgi?pkg_info++NetBSD-current) command with no arguments.
24:
25: $ pkg_info
26:
27:
28: ## Determine which software requires upgrading
29:
30: To determine which software requires upgrading, you have to install pkg_chk first, which is available in [pkgtools/pkg_chk](http://pkgsrc.se/pkgtools/pkg_chk) from pkgsrc. When done, asure that your pkgsrc tree is up to date and enter:
31:
32: # pkg_chk -q -u
33:
34:
35: to see which packages needs to be upgraded.
36:
37: ## Upgrade installed software
38:
39: There are many ways to upgrade installed software use one of the following
40:
41: * pkgtools/[pkg_rolling-replace](http://pkgsrc.se/pkgtools/pkg_rolling-replace)
42: * pkgtools/[pkg_chk](http://pkgsrc.se/pkgtools/pkg_chk)
43:
44: or use `make update` in the pkgsrc directory of the package that needs to be updated.
45:
46: ## Determine which software have outstanding security advisories
47:
48: You can use pkgsrc's auditing feature to (periodicaly) check for package vulnerabilites.
49:
50: Install [security/audit-packages](http://pkgsrc.se/security/audit-packages) first.
51:
52: _If you dont know how to install a package, read the section about installing packages, or the [pkgsrc user guide](http://www.netbsd.org/docs/pkgsrc/).
53:
54: To audit the packages, you have to download the vulnerability list:
55:
56: # download-vulenability-list
57:
58:
59: You can put the following to your crontab to automate this:
60:
61: 0 3 * * * /usr/pkg/sbin/download-vulnerability-list >/dev/null 2>&1
62:
63:
64: This will update the vulnerability list every day at 3AM. You may wish to do this more often than once a day.
65:
66: You can also ask NetBSD to include the vulnerability check in the security report:
67:
68: Put this into `/etc/security.local`:
69:
70: if [ -x /usr/pkg/sbin/audit-packages ]; then
71: /usr/pkg/sbin/audit-packages
72: fi
73:
74:
75: ## Follow the instructions in a security advisory to apply a security patch
76:
77: # Securing the NetBSD Operating System
78:
79: ## Determine the system's security level
80:
81: See the value of `kern.securelevel` (cf. [sysctl(8)](http://netbsd.gw.com/cgi-bin/man-cgi?sysctl+8+NetBSD-current)) :
82:
83: $ sysctl kern.securelevel
84: kern.securelevel = 1
85:
86:
87: ## Recognize basic recommended access methods
88:
89: ## Configure an SSH server according to a set of requirements
90:
91: Edit `/etc/ssh/sshd_config`. When all seems fine, relaunch [sshd(8)](http://netbsd.gw.com/cgi-bin/man-cgi?sshd++NetBSD-current) daemon with :
92:
93: # /etc/rc.d/sshd restart
94:
95:
96: If you are working remotely via an SSH connexion, don't worry: with privileges separation (as default), your working connexion won't be claused.
97:
98: ## Configure an SSH server to use a key pair for authentication
99:
100: In `/etc/ssh/sshd_config`, uncomment lines:
101:
102: PasswordAuthentication no
103: PermitEmptyPasswords no
104:
105:
106: If you want to connect as root (don't do this), at least use keys with:
107:
108: PermitRootLogin without-password
109:
110:
111: Don't forget to relaunch daemon.
112:
113: ## Preserve existing SSH host keys during a system upgrade
114:
115: The SSH keys live under `/etc/ssh`. Just [tar(1)](http://netbsd.gw.com/cgi-bin/man-cgi?atr++NetBSD-current) up all key files and extract the archive on the new system.
116:
117: ## Recognize alternate authentication mechanisms
118:
119: ## Recognize alternate authorization schemes
120:
121: ## Recognize firewalls and rulesets
122:
123: To see input rules:
124:
125: # ipfstat -hin
126:
127:
128: `-o` (instead of `-i`) option gives output rules. `-6` option manipulates IPv6 rules. `-n` display groups and rules numbers, useful when searching from logs.
129:
130: IPNAT rules can be listed with:
131:
132: # ipnat -l
133:
134:
135: ## Recognize utilities that shape traffic or control bandwidth
136:
137: ## Recognize mechanisms for encrypting devices
138:
139: $ man cgd
140:
141:
142: ## Recognize methods for verifying the validity of binaries
143:
144: By default, `/etc/daily` launch `/etc/security` which uses [mtree(8)](http://netbsd.gw.com/cgi-bin/man-cgi?mtree++NetBSD-current).
145:
146:
147: To check if [veriexec(4)](http://netbsd.gw.com/cgi-bin/man-cgi?veriexec++NetBSD-current) is up:
148:
149:
150: $ sysctl kern.veriexec.strict
151: kern.veriexec.strict=1
152:
153:
154: Read [veriexec chapter](http://www.netbsd.org/docs/guide/en/chap-veriexec.html) from [NetBSD Guide](http://www.netbsd.org/docs/guide/en/) for more information.
155:
156: ## Enable exploit mitigation
157:
158: Follow advices in [security(8)](http://netbsd.gw.com/cgi-bin/man-cgi?security++NetBSD-current) man page.
159:
160:
161: ## Recognize methods for restraining a service
162:
163: * [chroot(8)](http://netbsd.gw.com/cgi-bin/man-cgi?chroot+8+NetBSD-current)
164: * [systrace(1)](http://netbsd.gw.com/cgi-bin/man-cgi?systrace+1+NetBSD-current)
165: * [Xen](http://www.netbsd.org/ports/xen)
166:
167: ## Modify the system banner
168:
169: Edit `/etc/motd`.
170:
171: You can also add a banner before SSH connexion; to do that, add:
172:
173: Banner /etc/ssh/issue
174:
175:
176: in `/etc/ssh/sshd_config` and put what you want to be displayed before SSH auth in file `/etc/ssh/issue`.
177:
178: # Files, Filesystems and Disks
179:
180: ## Mount or unmount local filesystems
181:
182: To mount a file system, use the [mount(8)](http://netbsd.gw.com/cgi-bin/man-cgi?mount++NetBSD-current) command. The general syntax is:
183:
184:
185: # mount [options] device_node mount_point
186:
187:
188: The available options may be found in the man page. Typically, it will be necessary to at least use the `-t` command to specify the type of filesystem to be mounted. For example, to mount a CD-ROM device, specify the ISO 9660 format with a command like the following:
189:
190: # mount -t cd9660 /dev/cd0d /mnt/cdrom
191:
192:
193: To unmount a mounted filesystem, use the [umount(8)](http://netbsd.gw.com/cgi-bin/man-cgi?umount++NetBSD-current) command. To unmount the mounted filesystem `/mnt/cdrom`, simply execute:
194:
195: # umount /mnt/cdrom
196:
197:
198: Note that unmounting a filesystem will fail if any running process has a directory in that filesystem as its present working directory. For example:
199:
200: # mount -t cd9660 /dev/cd0d /mnt/cdrom
201: # cd /mnt/cdrom
202: # umount /mnt/cdrom
203: umount: /mnt/cdrom: Device busy
204: # cd
205: # umount /mnt/cdrom
206: #
207:
208:
209: ## Configure data to be available through NFS
210:
211: Let's share `/export/data`. Create the file `/etc/exports` as:
212:
213: $ cat /etc/exports
214: /export/data -maproot=nobody -ro -network 192.168.1.0 -mask 255.255.255.0
215:
216:
217: Here, the file system will be read only (option `-ro`), available only for clients from `192.168.1.0/24` and root access from clients will be mapped as `nobody` access on server (we don't have confidence with our clients). The syntax and options are documented in [exports(5)](http://netbsd.gw.com/cgi-bin/man-cgi?exports+5+NetBSD-current).
218:
219: We have to start [rpcbind(8)](http://netbsd.gw.com/cgi-bin/man-cgi?rpcbind+8+NetBSD-current), [mountd(8)](http://netbsd.gw.com/cgi-bin/man-cgi?mountd+8+NetBSD-current), [rpc.lockd(8)](http://netbsd.gw.com/cgi-bin/man-cgi?rpc.lockd+8+NetBSD-current), [nfsd(8)](http://netbsd.gw.com/cgi-bin/man-cgi?nfsd+8+NetBSD-current) and [rpc.statd(8)](http://netbsd.gw.com/cgi-bin/man-cgi?rpc.statd+8+NetBSD-current). In order to do that, edit `/etc/rc.conf` and set:
220:
221: rpcbind=YES rpcbind_flags="-l"
222: mountd=YES
223: nfs_server=YES
224: statd=YES
225: lockd=YES
226:
227:
228: The flag `-l` tells [rpcbind(8)](http://netbsd.gw.com/cgi-bin/man-cgi?rpcbind+8+NetBSD-current) to use _libwrap_ ([hosts_options(5)](http://netbsd.gw.com/cgi-bin/man-cgi?hosts_options+5+NetBSD-current)). Edit the `/etc/hosts.access` and set:
229:
230: rpcbind: 192.168.1.0/255.255.255.0 ALLOW
231:
232:
233: to allow clients to connect to the server.
234:
235: On the clients, we have to start [rpcbind(8)](http://netbsd.gw.com/cgi-bin/man-cgi?rpcbind+8+NetBSD-current), [rpc.statd(8)](http://netbsd.gw.com/cgi-bin/man-cgi?rpc.statd+8+NetBSD-current) and [rpc.lockd(8)](http://netbsd.gw.com/cgi-bin/man-cgi?rpc.lockd+8+NetBSD-current); edit `/etc/rc.conf` and set:
236:
237: rpcbind=YES rpcbind_flags="-l"
238: nfs_client=YES
239: statd=YES
240: lockd=YES
241:
242:
243: Now, lets mount the file system on the client:
244:
245: # mount -o ro server:/export/data /data
246: $ mount | grep data
247: server:/export/data on /data type nfs (read-only)
248:
249:
250: Don't forget to add a line in `/etc/fstab` ([fstab(5)](http://netbsd.gw.com/cgi-bin/man-cgi?fstab+5+NetBSD-current)):
251:
252:
253: server:/export/data /data nfs ro 0 0
254:
255:
256: to mount the file system at boot time. That's all.
257:
258: See the NetBSD Guide [[1]](http://www.netbsd.org/docs/guide/en/chap-net-misc.html#chap-net-misc-nfs) for more details.
259:
260: ## Determine which filesystems are currently mounted and which will be mounted at system boot
261:
262: A list of currently mounted filesystems can be obtained by running the [mount(8)](http://netbsd.gw.com/cgi-bin/man-cgi?mount++NetBSD-current) command without any arguments.
263:
264: The file [fstab(5)](http://netbsd.gw.com/cgi-bin/man-cgi?fstab++NetBSD-current) in `/etc` contains information about which files are mounted at system boot and what options they are mounted with, whether they should be [fsck(8)](http://netbsd.gw.com/cgi-bin/man-cgi?fsck++NetBSD-current)ed and if so in what order, etc.
265:
266: ## Determine disk capacity and which files are consuming the most disk space
267:
268: Disk capacity:
269:
270: $ df -h
271:
272:
273: Find the size of files in a directory:
274:
275: $ du -sk
276:
277:
278: Report by file size:
279:
280: $ du -k | sort -n
281:
282:
283: ## Create and view symbolic or hard links
284:
285: Symbolic link:
286:
287: $ ln -s sourcefile targetfile
288:
289:
290: Hard link:
291:
292: $ ln sourcefile targetfile
293:
294:
295: ## View file permissions and modify them using either symbolic or octal mode
296:
297: View file permissions:
298:
299: $ ls -l filename
300:
301:
302: Change file permissions
303:
304: $ chmod 644 filename
305:
306:
307: ## Modify a file's owner or group
308:
309: The [chown(8)](http://netbsd.gw.com/cgi-bin/man-cgi?chown++NetBSD-current) command can be used to modify a file's owner or group.
310:
311:
312: To change the owner of the file `somefile` to the user `someuser`, execute:
313:
314: chown someuser somefile
315:
316:
317: Similarly, to change the group of the file `somefile` to the group `somegroup`, execute:
318:
319: chown :somegroup somefile
320:
321:
322: If you like, can change both the group and owner of a file with a single command. To implement both of the modifications made by the two commands above, execute:
323:
324: chown someuser:somegroup somefile
325:
326:
327: Note that there is also a [chgrp(1)](http://netbsd.gw.com/cgi-bin/man-cgi?chgrp++NetBSD-current) command to change the group of a file.
328:
329:
330: To change the group of the file `somefile` to the group `somegroup`, execute:
331:
332: chgrp somegroup somefile
333:
334:
335: ## Backup and restore a specified set of files and directories to local disk or tape
336:
337: Create your (compressed) archive with:
338:
339: $ tar cvfz backup.tgz somedirectory/
340:
341:
342: * `c` option: create the archive,
343: * `z` option: compress the archive whith [gzip(1)](http://netbsd.gw.com/cgi-bin/man-cgi?gzip++NetBSD-current),
344: * `f` option: output to a file; if you miss this option, [tar(1)](http://netbsd.gw.com/cgi-bin/man-cgi?tar++NetBSD-current) will output archive to `/dev/st0` (default tape),
345: * `v` option: verbose output ie. files added to archive will be displayed.
346:
347: To restore, use:
348:
349: $ tar xzpf backup.tgz
350:
351:
352: * `x` option: extract the archive,
353: * `p` option: preserve ownership.
354:
355: See also [pax(1)](http://netbsd.gw.com/cgi-bin/man-cgi?pax++NetBSD-current) and [cpio(1)](http://netbsd.gw.com/cgi-bin/man-cgi?cpio++NetBSD-current).
356:
357: ## Backup and restore a file system
358:
359: # dump 0f - | (cd /altroot; retore rf -)
360:
361:
362: See [dump(8)](http://netbsd.gw.com/cgi-bin/man-cgi?dump++NetBSD-current) and [restore(8)](http://netbsd.gw.com/cgi-bin/man-cgi?restore++NetBSD-current).
363:
364:
365: ## Backup using ffs snapshots
366:
367: Snapshots allows to work with an atomic file system copy taken at a the time of the snapshot. This is very useful to for instance backup a file system on which there may be running database applications such as PostgreSQL, without the need to stop and restart the database application.
368:
369: See [fssconfig(8)](http://netbsd.gw.com/cgi-bin/man-cgi?fssconfig++NetBSD-current) and [fss(4)](http://netbsd.gw.com/cgi-bin/man-cfi?fss++NetBSD-current) for more details. Here for the sake of an example we will suppose that we want to backup a live `/` file system using `rsync` to a `/backup` file system.
370:
371:
372: Let's first create the "atomic" snapshot of the `/` file system:
373:
374: # fssconfig -cx fss0 / /tmp/back
375:
376:
377: We now have configured the device `/dev/fss0` to be a snapshot mirror of the `/` file system, using a temporary log of `/tmp/back` to which new writes will be added for as long as the snapshot device is configured. This file will be automatically deleted at device unconfiguration because of the optional `-x` switch. You may now use that device with the `dump` command or mount it and use other backup commands such as `pax`, `tar` or `rsync` as you wish.
378:
379: # mount -o ro /dev/fss0 /mnt
380:
381:
382: We have now mounted the atomic copy of the file system to `/mnt`. Let's update our `/backup` file system from it:
383:
384: # rsync -vaHx --delete /mnt/ /backup/
385:
386:
387: So our "atomic" live backup is done and we now no longer need our snapshot:
388:
389: # umount /mnt
390: # fssconfig -u fss0
391:
392:
393: ## Determine the directory structure of a system
394:
395: ## Manually run the file system checker and repair tool
396:
397: For FFS filesystems (example, in this case is the first slice on your first IDE hard disk):
398:
399: # fsck /dev/rwd0a
400:
401:
402: The `-y` option should be added with caution: [fsck(8)](http://netbsd.gw.com/cgi-bin/man-cgi?fsck+8+NetBSD-current) assumes yes as the default answer for all its questions. Use it at your own risks.
403:
404:
405: ## View and modify file flags
406:
407: use chflags to modify file flags, for example:
408:
409: $ chflag uchange pkgsrc.tar.gz
410: $ ls -lo pkgsrc.tar.gz
411: -rw-r--r-- 1 zafer users uchg 32072480 May 19 09:12 pkgsrc.tar.gz
412:
413:
414: ## Monitor the virtual memory system
415:
416: # Users and Accounts Management
417:
418: ## Protect authentication data
419:
420: ## Create, modify and remove user accounts
421:
422: create
423:
424: # useradd -m johndoe
425:
426:
427: delete
428:
429: # userdel johndoe
430:
431:
432: modify
433:
434: # usermod -m -d /home/foo johndoe
435:
436:
437: ## Create a system account
438:
439: ## Control which files are copied to a new user's home directory during account creation
440:
441: The _-k_ option of the [useradd(8)](http://netbsd.gw.com/cgi-bin/man-cgi?useradd++NetBSD-current) command can be used to specify a "skeleton directory". The contents of the specified skeleton directory will be copied to the new user's home directory. If no skeleton directory is specified with _-k_, the default of `/usr/skel/` is used.
442:
443:
444: ## Change a password
445:
446: The [passwd(1)](http://netbsd.gw.com/cgi-bin/man-cgi?passwd++NetBSD-current) command can be used to change a password.
447:
448:
449: Executing passwd with no arguments will change the password of the executing user. The existing password must be supplied before changes can be made. The new password must be entered identically twice, to ensure the password is not set to a misspelling of the intended password. The process looks something like this - note that passwords do not echo:
450:
451: $ passwd
452: Changing local password for user.
453: Old password:
454: New password:
455: Retype new password:
456:
457:
458: The superuser may change the password of an arbitrary user by supplying that user's name as the only argument to passwd. Root does not need to supply the user's existing password, and may simply supply a new one. The process looks something like this:
459:
460: # passwd user
461: Changing local password for user.
462: New password:
463: Retype new password
464:
465:
466: ## Force the user to change their password upon next login
467:
468: # usermod -F johndoe
469:
470:
471: ## Change the encryption algorithm used to encrypt the password database
472:
473: The encryption algorithm or algorithms used to encrypt the password database are specified in the [passwd.conf(5)](http://netbsd.gw.com/cgi-bin/man-cgi?passwd.conf++NetBSD-current) file in `/etc`.
474:
475:
476: The syntax of the file is straightforward and is made clear by the following example, taken from the man page:
477:
478: _Use MD5 as the local cipher and old-style DES as the YP cipher. Use blowfish with 2^5 rounds for root:_
479:
480: default:
481: localcipher = md5
482: ypcipher = old
483:
484:
485: root:
486: localcipher = blowfish,5
487:
488:
489: The algorithm choices are: `old', `newsalt,<rounds>', `md5', `sha1,<rounds>', and `blowfish,<rounds>'. Consult the man page for details on allowable round parameters.
490:
491: ## Change a user's default shell
492:
493: Make your market in `/etc/shells` file and pick up one. For example, we want to change the shell of _johndoe_ to `/bin/ksh`:
494:
495: # chsh -s /bin/ksh johndoe
496:
497:
498: or
499:
500: # chpass -s /bin/ksh johndoe
501:
502:
503: See [chsh(1)](http://netbsd.gw.com/cgi-bin/man-cgi?chsh+1+NetBSD-current) for mor details.
504:
505:
506: ## Lock a user account or reset a locked user account
507:
508: Lock
509:
510: # usermod -C yes johndoe
511:
512:
513: Unlock
514:
515: # usermod -C no johndoe
516:
517:
518: ## Determine identity and group membership
519:
520: $ id
521:
522:
523: ## Determine who is currently on the system or the last time a user was on the system
524:
525: Enter
526:
527: $ w
528:
529:
530: to determine who is currently on the system.
531:
532: Enter
533:
534: $ last
535:
536:
537: to determine the last time a user was on the system.
538:
539: ## Enable accounting and view system usage statistics
540:
541: # Basic System Administration
542:
543: ## Determine which process are consuming the most CPU
544:
545: The [top(1)](http://netbsd.gw.com/cgi-bin/man-cgi?top++NetBSD-current) command displays and regularly updates a list of top CPU consuming processes. The list includes details such as the command used to create the process, the user who ran that command, the process' PID, what state the process is currently in and how much memory and CPU time the process is consuming.
546:
547:
548: ## View and send signals to active processes
549:
550: The [ps(1)](http://netbsd.gw.com/cgi-bin/man-cgi?ps++NetBSD-current) command can be used to view a list of names and details (such as PID) currently active processes. Exactly which processes and what details about them are displayed can be customised using the options described in the man page. To get the default details of _all_ processes, execute:
551:
552:
553: $ ps ax
554:
555:
556: Sending signals to processes is done using the [kill(1)](http://netbsd.gw.com/cgi-bin/man-cgi?kill++NetBSD-current) command. The signal to be sent may be specified either by name (e.g. HUP, INT, QUIT, ABRT, KILL, ALRM, TERM; see also `kill -l` output) or by an integer code, as specified in the man page.
557:
558:
559: The simplest syntax for [kill(1)](http://netbsd.gw.com/cgi-bin/man-cgi?kill++NetBSD-current) is:
560:
561:
562: $ kill {signal name or code} pid
563:
564:
565: where `pid` is the PID of the process to be killed. Note that if no signal name or code is specified (i.e. just `kill pid` is used) then a TERM signal is sent by default.
566:
567: Note that it is not typical to immediately know the PID of a process one wants to signal. One can either use the [ps(1)](http://netbsd.gw.com/cgi-bin/man-cgi?ps++NetBSD-current) command as described above to find the pid (perhaps with the assistance of [grep(1)](http://netbsd.gw.com/cgi-bin/man-cgi?grep++NetBSD-current), or one can use the [pkill(1)](http://netbsd.gw.com/cgi-bin/man-cgi?pkill++NetBSD-current) command, which works like [kill(1)](http://netbsd.gw.com/cgi-bin/man-cgi?kill++NetBSD-current) except that it accepts a process name rather than a PID.
568:
569: ## Use an rc(8) script to determine if a service is running and start, restart or stop it as required
570:
571: To see if a service is running, execute that service's [rc(8)](http://netbsd.gw.com/cgi-bin/man-cgi?rc++NetBSD-current) script with an argument of `status`. The output will indicate if that service is running. Not all rc scripts have a `status` option. For example:
572:
573:
574: # /etc/rc.d/sshd status
575: sshd is not running.
576: # /etc/rc.d/sshd start
577: # /etc/rc.d/sshd status
578: sshd is running as pid 383.
579: # /etc/rc.d/sshd stop
580:
581:
582:
583: Note that while every script in `/etc/rc.d` is _supposed_ to accept the `status` argument, many do not.
584:
585: If a service is not running, it can be started by executing its [rc(8)](http://netbsd.gw.com/cgi-bin/man-cgi?rc++NetBSD-current) script with an argument of `start`. Once a service is running, it can be restarted or stopped in a similar manner, using the arguments `restart` and `stop`.
586:
587:
588: Note that an rc script can not launch a service if this service is not marked as runable in `/etc/rc.conf` (via `service=YES` entry).
589:
590: ## Configure a service to start at boot time
591:
592: Add or copy the rc skript to /etc/rc.d/ and then add the service to your /etc/rc.conf
593:
594: ## View and configure system hardware
595:
596: View pci bus (use pci0 - 2)
597:
598: $ pcictl /dev/pci0 list
599:
600:
601: ## View, load, or unload a kernel module
602:
603: View
604:
605: $ modstat
606:
607:
608: Load
609:
610: # modload file
611:
612:
613: Unload
614:
615: # modunload -i id
616:
617:
618: See the manual page for lkm.conf(5) for information on how to automatically load modules at boot time. Please note that for this to work, lkm=YES must be set in /etc/rc.conf. Also note the critical_filesystems_local setting in rc.conf(5), which may be required for bootloaded modules located under /usr if /usr is on a separate partition than /.
619:
620: ## Modify a kernel parameter on the fly
621:
622: # sysctl -w <variable>=<value>
623:
624:
625: ## View the status of a software RAID mirror or stripe
626:
627: Verify parity:
628:
629: # raidctl -p raid0
630: /dev/rraid0c: Parity status: clean
631:
632:
633: View configuration and state:
634:
635: # raidctl -s raid0
636:
637:
638: [raidctl(8)](http://netbsd.gw.com/cgi-bin/man-cgi?raidctl++NetBSD-current) man page is very useful, don't miss it.
639:
640: ## Configure system logging
641:
642: Verify that [syslogd(8)](http://netbsd.gw.com/cgi-bin/man-cgi?syslogd++NetBSD-current) is running. If not, enable it in `/etc/rc.conf` and launch it:
643:
644:
645: # /etc/rc.d/syslogd start
646:
647:
648: The logging daemon is configured with `/etc/syslog.conf` (see [syslog.conf(5)](http://netbsd.gw.com/cgi-bin/man-cgi?syslog.conf++NetBSD-current). When you have modified this file, you have to tell to the daemon to reread it:
649:
650:
651: # pkill -HUP syslogd
652:
653:
654: by sending a `SIGHUP`.
655:
656: If you add files in `/etc/syslog.conf`, don't forget to configure rotation in `/etc/newsyslog.conf` ([newsyslog.conf(5)](http://netbsd.gw.com/cgi-bin/man-cgi?newsyslog.conf++NetBSD-current)).
657:
658:
659: If the original daemon's filtering features are too poor for you, try [sysutils/syslog-ng](http://pkgsrc.se/sysutils/syslog-ng) package.
660:
661: To log signals sent to processes:
662:
663: # sysctl -w kern.logsigexit=1
664:
665:
666: ## Review log files to troubleshoot and monitor system behavior
667:
668: $ tail -f /var/log/messages |grep daemon
669:
670:
671: Try also these packages:
672:
673: * [misc/root-tail](http://pkgsrc.se/misc/root-tail) or [misc/xtail](http://pkgsrc.se/misc/xtail) if you use X11,
674: * [misc/colortail](http://pkgsrc.se/misc/colortail) or [misc/mail](http://pkgsrc.se/misc/mtail) if you want colors,
675: * [sysutils/wtail](http://pkgsrc.se/sysutils/wtail) or [misc/multitail](http://pkgsrc.se/misc/multitail) to view multiples files.
676:
677: ## Determine which MTA is being used on the system
678:
679: $ less /etc/mailer.conf
680:
681:
682: ## Create or modify email aliases for Sendmail or Postfix
683:
684: ## View the Sendmail or Postfix mail queue
685:
686: $ mailq
687:
688:
689: ## Read mail on the local system
690:
691: $ mail
692:
693:
694: ## Understand basic printer troubleshooting
695:
696: ## Halt, reboot, or bring the system to single-user mode
697:
698: to halt enter:
699:
700: # shutdown -h now
701:
702:
703: to reboot enter either:
704:
705: # reboot
706:
707:
708: or
709:
710: # shutdown -r now
711:
712:
713: to bring the system to single-user mode press any key during boot countdown and then enter:
714:
715: boot -s
716:
717:
718: From multi-user mode, you should:
719:
720: # kill -TERM 1
721:
722:
723: to return to single-user mode.
724:
725: ## Recognize the difference between hard and soft limits and modify existing resource limits
726:
727: ## Recognize common, possibly third-party, server configuration files
728:
729: ## Configure the scripts that run periodically to perform various system maintenance tasks
730:
731: ## Determine the last system boot time and the workload on the system
732:
733: $ uptime
734:
735:
736: or
737:
738: $ w
739:
740:
741: ## Monitor disk input/output
742:
743: $ iostat -w 1
744:
745:
746: ## Deal with busy devices
747:
748: ## Determine information regarding the operating system
749:
750: $ uname -a
751:
752:
753: ## Understand the advantages of using a BSD license
754:
755: # Network Administration
756:
757: ## Determine the current TCP/IP settings on a system
758:
759: First, see the interfaces which are connected:
760:
761: $ ifconfig -ls
762: wm0 wm1 wm2 wm3 wm4 lo0 pflog0 vlan0 vlan1 vlan2 vlan3
763:
764:
765: To see the IP adress of an interface:
766:
767: $ ifconfig vlan3
768: vlan3: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> mtu 1500
769: vlan: 847 parent: wm4
770: address: 00:04:23:af:f1:e4
771: inet 172.17.13.254 netmask 0xfffffe00 broadcast 172.17.13.255
772:
773:
774: We have the MAC (hardware adress, here `00:04:23:af:f1:e4`) and the IP adress with netmask (here `172.17.13.254` with `255.255.254.0`).
775:
776: Now, we want to know IPv4 routing settings:
777:
778: $ netstat -rn -f inet | head -5
779: Routing tables
780:
781: Internet:
782: Destination Gateway Flags Refs Use Mtu Interface
783: default 172.16.200.130 UG1 0 9607369 - wm0
784:
785:
786: The default route is tagged `default`, here it is `172.16.200.130` on `wm0` interface.
787:
788: See [ifconfig(8)](http://netbsd.gw.com/cgi-bin/man-cgi?ifconfig+8+NetBSD-current) and [netstat(8)](http://netbsd.gw.com/cgi-bin/man-cgi?netstat+8+NetBSD-current) for more details.
789:
790: ## Set a system's TCP/IP settings
791:
792: # ifconfig fxp0 192.168.0.1 netmask 255.255.255.0 up
793:
794:
795: ## Determine which TCP or UDP ports are open on a system
796:
797: $ sockstat -cl
798:
799:
800: ## Verify the availability of a TCP/IP service
801:
802: $ sockstat -l
803:
804:
805: ## Query a DNS server
806:
807: Find responsible nameservers for a given domain
808:
809: $ dig ns netbsd.org
810:
811:
812: Query a DNS server
813:
814: $ dig @adns1.berkeley.edu A www.netbsd.org
815:
816:
817: ## Determine who is responsible for a DNS zone
818:
819: Use [dig(1)](http://netbsd.gw.com/cgi-bin/man-cgi?dig+1+NetBSD-current) to check the SOA section:
820:
821:
822: $ dig www.netbsd.org soa
823: ; <<>> DiG 9.3.2 <<>> www.netbsd.org soa
824: ;; global options: printcmd
825: ;; Got answer:
826: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 22618
827: ;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 1, ADDITIONAL: 0
828:
829: ;; QUESTION SECTION:
830: ;www.netbsd.org. IN SOA
831:
832: ;; AUTHORITY SECTION:
833: netbsd.org. 10800 IN SOA ns.netbsd.org. hostmaster.netbsd.org. 2007032701 21600 10800 2419200 86400
834:
835: ;; Query time: 163 msec
836: ;; SERVER: 191.168.1.1#53(191.168.1.1)
837: ;; WHEN: Sun Jul 1 11:56:27 2007
838: ;; MSG SIZE rcvd: 92
839:
840:
841: The master server is `ns.netbsd.org` and the responsible is `hostmaster [at] netbsd [dot] org`.
842:
843: ## Change the order of name resolution
844:
845: You live in `home.org` but you often work on hosts in `work.com`. To avoid typing FQDN all the time, put this in `/etc/resolv.conf`:
846:
847: nameserver 1.2.3.4
848: nameserver 5.6.7.8
849: domain home.org
850: search home.org work.com
851:
852:
853: The first two lines say which DNS servers to use. The third says that the resolver has to search host first in `home.org`. The last tells it search also in `work.com`. After that, you should have:
854:
855: $ host www
856: www.work.com has address 192.168.1.2
857:
858:
859: ## Convert a subnet mask between dotted decimal, hexadecimal or CIDR notation
860:
861: Use either:
862:
863: * [net/ipcalc](http://pkgsrc.se/net/ipcalc)
864: * [net/cidr](http://pkgsrc.se/net/cidr)
865: * [net/sipcalc](http://pkgsrc.se/net/sipcalc)
866:
867:
868: ## Gather information using an IP address and subnet mask
869:
870: ## Understand IPv6 address theory
871:
872: ## Demonstrate basic tcpdump(1) skills
873:
874: # tcpdump -i fxp0 not port 22
875:
876:
877: ## Manipulate ARP and neighbor discovery caches
878:
879: View ARP cache
880:
881: $ arp -a
882:
883:
884: ## Configure a system to use NTP
885:
886: * Edit `/etc/ntp.conf` and choose from the list at least two servers, or add two new ones. The time servers should be located as close as possible (network topology) to your server.
887:
888: * Add `ntpd=yes` to `/etc/rc.conf`
889:
890: * Start the ntp daemon by entering: `/etc/rc.d/ntpd start`
891:
892: * Verify the service, by entering `ntpq` and then `peers`.
893:
894: ## View and renew a DHCP lease
895:
896: Renew a DHCP lease
897:
898: # dhcpcd -k
899: # dhcpcd
900:
901:
902: ## Recognize when and how to set or remove an interface alias
903:
904: set alias
905:
906: # ifconfig fxp0 inet 192.168.0.2 netmask 255.255.255.0 alias
907:
908:
909: remove alias
910:
911: # ifconfig fxp0 inet 192.168.0.2 netmask 255.255.255.0 -alias
912:
913:
914: # Basic Unix Skills
915:
916: ## Demonstrate proficiency in using redirection, pipes and tees
917:
918: ### Output redirection
919:
920: $ ls > myfiles.txt
921:
922:
923: runs `ls` and redirects the output in the file myfiles.txt
924:
925: $ ls >> myfiles.txt
926:
927:
928: runs `ls` and appends the output to the file myfiles.txt
929:
930: ### Pipes
931:
932: $ ls -l | wc -l
933:
934:
935: runs `ls -l` and uses its output as the input for the command `wc -l`
936:
937: ## Recognize, view and modify environmental variables
938:
939: ### Viewing environmental variables
940:
941: On sh based shells like sh, ksh, bash this is done with the command `export`
942:
943: $ export
944:
945:
946: On csh, tcsh with `env`
947:
948: $ env
949:
950:
951: ### Modifying environmental variables
952:
953: On sh based shells you assign the variable on the left side the value on the right side using an equal sign.
954:
955: $ export MYVAR="hello kitty"
956:
957:
958: On csh, tcsh to assign use a single space instead of an equal sign.
959:
960: $ setenv MYVAR "hello kitty"
961:
962:
963: ## Be familiar with the vi(1) editor
964:
965: hjkl movement
966:
967: i insert
968:
969: 0 beginning of line
970:
971: $ end of line
972:
973: o/O insert new line
974:
975: x/X delete char
976:
977: w/W Word
978:
979: e/E End of word
980:
981: b/B begin of word
982:
983: dd delete a line
984:
985: yy yank a line
986:
987: ## Determine if a file is a binary, text, or data file
988:
989: The [file(1)](http://netbsd.gw.com/cgi-bin/man-cgi?file++NetBSD-current) command is capable of discerning between executable (binary) files, text files and data files. In many cases it is able to determine further information about data files, e.g. it can recognise image files as being GIFs or JPGs.
990:
991:
992: $ file /bin/sh
993: /bin/sh: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for NetBSD 4.99.72, dynamically linked (uses shared libs), not stripped
994:
995:
996: $ file /etc/wscons.conf
997: /etc/wscons.conf: ASCII English text
998:
999:
1000: $ file AnsweringMachine.ogg
1001: AnsweringMachine.ogg: Ogg data, Vorbis audio, stereo, 44100 Hz, ~256000 bps, created by: Xiph.Org libVorbis I (1.1.0 RC1)
1002:
1003:
1004: $ file photo.jpg
1005: photo.jpg: JPEG image data, JFIF standard 1.01
1006:
1007:
1008: ## Locate files and binaries on a system
1009:
1010: Binaries
1011:
1012: $ whereis netstat
1013:
1014:
1015: ## Overcome command line length limitations
1016:
1017: ## Find a file with a given set of attributes
1018:
1019: ## Create a simple Bourne shell script
1020:
1021: vi myshellscript.sh
1022:
1023:
1024: ## Find appropriate documentation
1025:
1026: $ apropos keyword
1027: $ man command
1028:
1029:
1030: ## Recognize the different sections of the manual
1031:
1032: Sections are from 1 to 9
1033:
1034: * 1 General commands manual
1035:
1036: $ man 1 df
1037:
1038:
1039: * 2 System calls manual
1040:
1041: $ man 2 lseek
1042:
1043:
1044: * 3 Library functions manual
1045:
1046: $ man 3 sprintf
1047:
1048:
1049: * 4 Kernel interfaces manual
1050:
1051: $ man 4 null
1052:
1053:
1054: * 5 File formats manual
1055:
1056: $ man 5 exports
1057:
1058:
1059: * 6 Games manual
1060:
1061: $ man 6 tetris
1062:
1063:
1064: * 7 Miscellanea
1065:
1066: $ man 7 me
1067:
1068:
1069: * 8 System manager's manual
1070:
1071: $ man 8 reboot
1072:
1073:
1074: * 9 Kernel developer's manual
1075:
1076: $ man 9 kauth
1077:
1078:
1079: ## Verify a file's message digest fingerprint (checksum)
1080:
1081: Depending on what sort of digest is used enter either:
1082:
1083: $ md5 _filename_
1084:
1085:
1086: or
1087:
1088: $ sha1 _filename_
1089:
1090:
1091: and compare the output.
1092:
1093: ## Demonstrate familiarity with the default shell
1094:
1095: ## Use job control
1096:
1097: List jobs
1098:
1099: $ jobs -l
1100:
1101:
1102: Put job into background
1103:
1104: # /usr/libexec/locate.updatedb &
1105:
1106:
1107: Put job into foreground
1108:
1109: # fg pid
1110:
1111:
1112: Put job into background
1113:
1114: # bg pid
1115:
1116:
1117: ## Demonstrate proficiency with regular expressions
1118:
1119: ## Understand various "domain" contexts
1120:
1121: ## Configure an action to be scheduled by cron(8)
1122:
1123: There are two ways to accomplish this task. You either put the cronjob in the global crontab file `/etc/crontab` or you edit your own crontab with `crontab -e`.
1124:
1125: $ crontab -e
1126:
1127:
1128: (this command invokes your favorite text editor specified by `$EDITOR` environment variable or `VISUAL`, by default `/usr/bin/vi`).
1129:
1130: Add a cronjob:
1131:
1132: 0 23 * * * sh /my/home/shellskript
1133:
1134:
1135: Here, the script will be run all days at 23:00. The fields order is minute, hour, day of month, month and day of week; the last field is the command to run. See [crontab(5)](http://netbsd.gw.com/cgi-bin/man-cgi?crontab+5+NetBSD-current) for details. List your current crontab:
1136:
1137:
1138: $ crontab -l
1139:
1140:
1141: As root you can see and edit any users crontab by supplying `-u` username
1142:
1143: # crontab -l -u john
1144:
1145:
1146: or edit it
1147:
1148: # crontab -e -u john
1149:
1150:
1151: When using the global `/etc/crontab` you have to supply the user who is executing the cronjob:
1152:
1153: # vi /etc/crontab
1154: 0 22 * * * john sh /johns/work/shellskript
1155:
1156:
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