1: # Miscellaneous operations
2:
3: This chapter collects various topics, in sparse order
4:
5: ## Installing the boot manager
6:
7: ### fdisk
8:
9: Sysinst, the NetBSD installation program, usually installs the NetBSD boot
10: manager on the hard disk. The boot manager can also be installed or reconfigured
11: at a later time, if needed, with the
12: [fdisk(8)](http://netbsd.gw.com/cgi-bin/man-cgi?fdisk+8+NetBSD-current)
13: command. For example:
14:
15: # fdisk -B wd0
16:
17: If NetBSD doesn't boot from the hard disk, you can boot it from the installation
18: floppy and start the kernel on the hard disk. Insert the installation disk and,
19: at the boot prompt, give the following command:
20:
21: > boot wd0a:netbsd
22:
23: This boots the kernel on the hard disk (use the correct device, for example sd0a
24: for a SCSI disk).
25:
26: *Note*: Sometimes `fdisk -B` doesn't give the expected result (at least it
27: happened to me), probably if you install/remove other operating systems like
28: Windows 95 or Linux with LILO. In this case, try running `fdisk -i` (which is
29: known as `fdisk /mbr` from DOS) and then run again `fdisk` from NetBSD.
30:
31: ### installboot
32:
33: There is another tool for installing a bootloader, named
34: [installboot(8)](http://netbsd.gw.com/cgi-bin/man-cgi?installboot+8+NetBSD-current).
35: Depending on the platform you are using, its usage differs, so you should read
36: the manpage and its extensive *EXAMPLES* section.
37:
38: E.g., if you want to install the bootloader for a ffs filesystem to the
39: partition you have your NetBSD in (in this case, `sd0c`), you would use:
40:
41: installboot -v /dev/rsd0c /usr/mdec/bootxx_ffs
42:
43: ## Deleting the disklabel
44:
45: Though this is not an operation that you need to perform frequently, it can be
46: useful to know how to do it in case of need. Please be sure to know exactly what
47: you are doing before performing this kind of operation. For example:
48:
49: # dd if=/dev/zero of=/dev/rwd0c bs=8k count=1
50:
51: The previous command deletes the disklabel (not the MBR partition table). To
52: completely delete the disk, the whole device `rwd0d` must be used. For example:
53:
54: # dd if=/dev/zero of=/dev/rwd0d bs=8k
55:
56: The commands above will only work as expected on the i386 and amd64 ports of
57: NetBSD. On other ports, the whole device will end in c, not d (e.g. `rwd0c`).
58:
59: ## Speaker
60:
61: I found this tip on a mailing list (I don't remember the author). To output a
62: sound from the speaker (for example at the end of a long script) the
63: [spkr(4)](http://netbsd.gw.com/cgi-bin/man-cgi?spkr+4+NetBSD-current)
64: driver can be used in the kernel config, which is mapped on `/dev/speaker`. For
65: example:
66:
67: echo 'BPBPBPBPBP' > /dev/speaker
68:
69: *Note*: The `spkr` device is not enabled in the generic kernel; a customized
70: kernel is needed.
71:
72: ## Forgot root password?
73:
74: If you forget root's password, not all is lost and you can still recover the
75: system with the following steps: boot single user, mount `/` and change root's
76: password. In detail:
77:
78: 1. Boot single user: when the boot prompt appears and the five seconds
79: countdown starts, give the following command:
80:
81: > boot -s
82:
83: 2. At the following prompt
84:
85: Enter pathname of shell or RETURN for sh:
86:
87: press Enter.
88:
89: 3. Write the following commands:
90:
91: # fsck -y /
92: # mount -u /
93: # fsck -y /usr
94: # mount /usr
95:
96: 4. Change root's password:
97:
98: # passwd root
99: Changing local password for root.
100: New password: (not echoed)
101: Retype new password: (not echoed)
102: #
103:
104: 5. Exit the shell to go to multiuser mode.
105:
106: # exit
107:
108:
109: If you get the error `Password file is busy`, please see the section below.
110:
111: ## Password file is busy?
112:
113: If you try to modify a password and you get the mysterious message `Password
114: file is busy, it probably means that the file `/etc/ptmp` has not been deleted
115: from the system. This file is a temporary copy of the `/etc/master.passwd` file;
116: check that you are not losing important information and then delete it:
117:
118: # rm /etc/ptmp
119:
120: *Note*: If the file `/etc/ptmp` exists you can also receive a warning message at
121: system startup. For example:
122:
123: root: password file may be incorrect - /etc/ptmp exists
124:
125: ## Adding a new hard disk
126:
127: This section describes how to add a new hard disk to an already working NetBSD
128: system. In the following example a new SCSI controller and a new hard disk,
129: connected to the controller, will be added. If you don't need to add a new
130: controller, skip the relevant part and go to the hard disk configuration. The
131: installation of an IDE hard disk is identical; only the device name will be
132: different (`wd#` instead of `sd#`).
133:
134: As always, before buying new hardware, consult the hardware compatibility list
135: of NetBSD or ask on a mailing list to make sure the new device is supported by
136: NetBSD.
137:
138: When the SCSI controller has been physically installed in the system and the new
139: hard disk has been connected, it's time to restart the computer and check that
140: the device is correctly detected, using the
141: [dmesg(8)](http://netbsd.gw.com/cgi-bin/man-cgi?dmesg+8+NetBSD-current)
142: command. This is the sample output for an NCR-875 controller:
143:
144: ncr0 at pci0 dev 15 function 0: ncr 53c875 fast20 wide scsi
145: ncr0: interrupting at irq 10
146: ncr0: minsync=12, maxsync=137, maxoffs=16, 128 dwords burst, large dma fifo
147: ncr0: single-ended, open drain IRQ driver, using on-chip SRAM
148: ncr0: restart (scsi reset).
149: scsibus0 at ncr0: 16 targets, 8 luns per target
150: sd0(ncr0:2:0): 20.0 MB/s (50 ns, offset 15)
151: sd0: 2063MB, 8188 cyl, 3 head, 172 sec, 512 bytes/sect x 4226725 sectors
152:
153: If the device doesn't appear in the output, check that it is supported by the
154: kernel that you are using; if necessary, compile a customized kernel (see
155: [[Compiling the kernel|guide/kernel]]).
156:
157: Now the partitions can be created using the
158: [fdisk(8)](http://netbsd.gw.com/cgi-bin/man-cgi?fdisk+8+NetBSD-current)
159: command. First, check the current status of the disk:
160:
161: # fdisk sd0
162: NetBSD disklabel disk geometry:
163: cylinders: 8188 heads: 3 sectors/track: 172 (516 sectors/cylinder)
164:
165: BIOS disk geometry:
166: cylinders: 524 heads: 128 sectors/track: 63 (8064 sectors/cylinder)
167:
168: Partition table:
169: 0: sysid 6 (Primary 'big' DOS, 16-bit FAT (> 32MB))
170: start 63, size 4225473 (2063 MB), flag 0x0
171: beg: cylinder 0, head 1, sector 1
172: end: cylinder 523, head 127, sector 63
173: 1: <UNUSED>
174: 2: <UNUSED>
175: 3: <UNUSED>
176:
177: In this example the hard disk already contains a DOS partition, which will be
178: deleted and replaced with a native NetBSD partition. The command
179: `fdisk -u sd0` allows to modify interactively the partitions. The modified data
180: will be written on the disk only before exiting and fdisk will request a
181: confirmation before writing, so you can work relaxedly.
182:
183: **Disk geometries**
184:
185: The geometry of the disk reported by fdisk can appear confusing. Dmesg reports
186: 4226725 sectors with 8188/3/172 for C/H/S, but 8188\*3\*172 gives 4225008 and
187: not 4226725. What happens is that most modern disks don't have a fixed geometry
188: and the number of sectors per track changes depending on the cylinder: the only
189: interesting parameter is the number of sectors. The disk reports the C/H/S
190: values but it's a fictitious geometry: the value 172 is the result of the total
191: number of sectors (4226725) divided by 8188 and then by 3.
192:
193: To make things more confusing, the BIOS uses yet another *fake* geometry (C/H/S
194: 524/128/63) which gives a total of 4225536, a value which is a better
195: approximation to the real one than 425008. To partition the disk we will use the
196: BIOS geometry, to maintain compatibility with other operating systems, although
197: we will lose some sectors (4226725 - 4225536 = 1189 sectors = 594 KB).
198:
199: To create the BIOS partitions the command `fdisk -u` must be used; the result is
200: the following:
201:
202: Partition table:
203: 0: sysid 169 (NetBSD)
204: start 63, size 4225473 (2063 MB), flag 0x0
205: beg: cylinder 0, head 1, sector 1
206: end: cylinder 523, head 127, sector 63
207: 1: <UNUSED>
208: 2: <UNUSED>
209: 3: <UNUSED>
210:
211: Now it's time to create the disklabel for the NetBSD partition. The correct
212: steps to do this are:
213:
214: # disklabel sd0 > tempfile
215: # vi tempfile
216: # disklabel -R -r sd0 tempfile
217:
218: If you try to create the disklabel directly with
219:
220: # disklabel -e sd0
221:
222: you get the following message
223:
224: disklabel: ioctl DIOCWDINFO: No disk label on disk;
225: use "disklabel -I" to install initial label
226:
227: because the disklabel does not yet exist on the disk.
228:
229: Now we create some disklabel partitions, editing the `tempfile` as already
230: explained. The result is:
231:
232: # size offset fstype [fsize bsize cpg]
233: a: 2048004 63 4.2BSD 1024 8192 16 # (Cyl. 0*- 3969*)
234: c: 4226662 63 unused 0 0 # (Cyl. 0*- 8191*)
235: d: 4226725 0 unused 0 0 # (Cyl. 0 - 8191*)
236: e: 2178658 2048067 4.2BSD 1024 8192 16 # (Cyl. 3969*- 8191*)
237:
238: *Note*: When the disklabel has been created it is possible to optimize it
239: studying the output of the command `newfs -N /dev/rsd0a`, which warns about
240: the existence of unallocated sectors at the end of a disklabel partition. The
241: values reported by newfs can be used to adjust the sizes of the partitions with
242: an iterative process.
243:
244: The final operation is the creation of the file systems for the newly defined
245: partitions (`a:` and `e:`).
246:
247: # newfs /dev/rsd0a
248: # newfs /dev/rsd0e
249:
250: The disk is now ready for usage, and the two partitions can be mounted. For
251: example:
252:
253: # mount /dev/sd0a /mnt
254:
255: If this succeeds, you may want to put an entry for the partition into
256: `/etc/fstab`.
257:
258: ## How to rebuild the devices in /dev
259:
260: First shutdown to single user, partitions still mounted `rw` (read-write); You
261: can do that by just typing `shutdown now` while you are in multi user mode, or
262: reboot with the `-s` option and make `/` and `/dev` read-writable by doing.
263:
264: # mount -u /
265: # mount -u /dev
266:
267: Then:
268:
269: # mkdir /newdev
270: # cd /newdev
271: # cp /dev/MAKEDEV* .
272: # sh ./MAKEDEV all
273: # cd /
274: # mv dev olddev
275: # mv newdev dev
276: # rm -r olddev
277:
278: Or if you fetched all the sources in `/usr/src`:
279:
280: # mkdir /newdev
281: # cd /newdev
282: # cp /usr/src/etc/MAKEDEV.local .
283: # ( cd /usr/src/etc ; make MAKEDEV )
284: # cp /usr/src/etc/obj*/MAKEDEV .
285: # sh ./MAKEDEV all
286: # cd /
287: # mv dev olddev; mv newdev dev
288: # rm -r olddev
289:
290: You can determine $arch by
291:
292: # uname -m
293:
294: or
295:
296: # sysctl hw.machine_arch
297:
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