1: **Contents**
2:
3: [[!toc levels=3]]
4:
5: # Miscellaneous operations
6:
7: This chapter collects various topics, in sparse order
8:
9: ## Installing the boot manager
10:
11: ### fdisk
12:
13: Sysinst, the NetBSD installation program, usually installs the NetBSD boot
14: manager on the hard disk. The boot manager can also be installed or reconfigured
15: at a later time, if needed, with the
16: [[!template id=man name="fdisk" section="8"]]
17: command. For example:
18:
19: # fdisk -B wd0
20:
21: If NetBSD doesn't boot from the hard disk, you can boot it from the installation
22: floppy and start the kernel on the hard disk. Insert the installation disk and,
23: at the boot prompt, give the following command:
24:
25: > boot wd0a:netbsd
26:
27: This boots the kernel on the hard disk (use the correct device, for example sd0a
28: for a SCSI disk).
29:
30: *Note*: Sometimes `fdisk -B` doesn't give the expected result (at least it
31: happened to me), probably if you install/remove other operating systems like
32: Windows 95 or Linux with LILO. In this case, try running `fdisk -i` (which is
33: known as `fdisk /mbr` from DOS) and then run again `fdisk` from NetBSD.
34:
35: ### installboot
36:
37: There is another tool for installing a bootloader, named
38: [[!template id=man name="installboot" section="8"]].
39: Depending on the platform you are using, its usage differs, so you should read
40: the manpage and its extensive *EXAMPLES* section.
41:
42: E.g., if you want to install the bootloader for a ffs filesystem to the
43: partition you have your NetBSD in (in this case, `sd0c`), you would use:
44:
45: installboot -v /dev/rsd0c /usr/mdec/bootxx_ffs
46:
47: ## Deleting the disklabel
48:
49: Though this is not an operation that you need to perform frequently, it can be
50: useful to know how to do it in case of need. Please be sure to know exactly what
51: you are doing before performing this kind of operation. For example:
52:
53: # dd if=/dev/zero of=/dev/rwd0c bs=8k count=1
54:
55: The previous command deletes the disklabel (not the MBR partition table). To
56: completely delete the disk, the whole device `rwd0d` must be used. For example:
57:
58: # dd if=/dev/zero of=/dev/rwd0d bs=8k
59:
60: The commands above will only work as expected on the i386 and amd64 ports of
61: NetBSD. On other ports, the whole device will end in c, not d (e.g. `rwd0c`).
62:
63: ## Speaker
64:
65: I found this tip on a mailing list (I don't remember the author). To output a
66: sound from the speaker (for example at the end of a long script) the
67: [[!template id=man name="spkr" section="4"]]
68: driver can be used in the kernel config, which is mapped on `/dev/speaker`. For
69: example:
70:
71: echo 'BPBPBPBPBP' > /dev/speaker
72:
73: *Note*: The `spkr` device is not enabled in the generic kernel; a customized
74: kernel is needed.
75:
76: ## Forgot root password?
77:
78: If you forget root's password, not all is lost and you can still recover the
79: system with the following steps: boot single user, mount `/` and change root's
80: password. In detail:
81:
82: 1. Boot single user: when the boot prompt appears and the five seconds
83: countdown starts, give the following command:
84:
85: > boot -s
86:
87: 2. At the following prompt
88:
89: Enter pathname of shell or RETURN for sh:
90:
91: press Enter.
92:
93: 3. Write the following commands:
94:
95: # fsck -y /
96: # mount -u /
97: # fsck -y /usr
98: # mount /usr
99:
100: 4. Change root's password:
101:
102: # passwd root
103: Changing local password for root.
104: New password: (not echoed)
105: Retype new password: (not echoed)
106: #
107:
108: 5. Exit the shell to go to multiuser mode.
109:
110: # exit
111:
112:
113: If you get the error `Password file is busy`, please see the section below.
114:
115: ## Password file is busy?
116:
117: If you try to modify a password and you get the mysterious message `Password
118: file is busy, it probably means that the file `/etc/ptmp` has not been deleted
119: from the system. This file is a temporary copy of the `/etc/master.passwd` file;
120: check that you are not losing important information and then delete it:
121:
122: # rm /etc/ptmp
123:
124: *Note*: If the file `/etc/ptmp` exists you can also receive a warning message at
125: system startup. For example:
126:
127: root: password file may be incorrect - /etc/ptmp exists
128:
129: ## Adding a new hard disk
130:
131: This section describes how to add a new hard disk to an already working NetBSD
132: system. In the following example a new SCSI controller and a new hard disk,
133: connected to the controller, will be added. If you don't need to add a new
134: controller, skip the relevant part and go to the hard disk configuration. The
135: installation of an IDE hard disk is identical; only the device name will be
136: different (`wd#` instead of `sd#`).
137:
138: As always, before buying new hardware, consult the hardware compatibility list
139: of NetBSD or ask on a mailing list to make sure the new device is supported by
140: NetBSD.
141:
142: When the SCSI controller has been physically installed in the system and the new
143: hard disk has been connected, it's time to restart the computer and check that
144: the device is correctly detected, using the
145: [[!template id=man name="dmesg" section="8"]]
146: command. This is the sample output for an NCR-875 controller:
147:
148: ncr0 at pci0 dev 15 function 0: ncr 53c875 fast20 wide scsi
149: ncr0: interrupting at irq 10
150: ncr0: minsync=12, maxsync=137, maxoffs=16, 128 dwords burst, large dma fifo
151: ncr0: single-ended, open drain IRQ driver, using on-chip SRAM
152: ncr0: restart (scsi reset).
153: scsibus0 at ncr0: 16 targets, 8 luns per target
154: sd0(ncr0:2:0): 20.0 MB/s (50 ns, offset 15)
155: sd0: 2063MB, 8188 cyl, 3 head, 172 sec, 512 bytes/sect x 4226725 sectors
156:
157: If the device doesn't appear in the output, check that it is supported by the
158: kernel that you are using; if necessary, compile a customized kernel (see
159: [[Compiling the kernel|guide/kernel]]).
160:
161: Now the partitions can be created using the
162: [[!template id=man name="fdisk" section="8"]]
163: command. First, check the current status of the disk:
164:
165: # fdisk sd0
166: NetBSD disklabel disk geometry:
167: cylinders: 8188 heads: 3 sectors/track: 172 (516 sectors/cylinder)
168:
169: BIOS disk geometry:
170: cylinders: 524 heads: 128 sectors/track: 63 (8064 sectors/cylinder)
171:
172: Partition table:
173: 0: sysid 6 (Primary 'big' DOS, 16-bit FAT (> 32MB))
174: start 63, size 4225473 (2063 MB), flag 0x0
175: beg: cylinder 0, head 1, sector 1
176: end: cylinder 523, head 127, sector 63
177: 1: <UNUSED>
178: 2: <UNUSED>
179: 3: <UNUSED>
180:
181: In this example the hard disk already contains a DOS partition, which will be
182: deleted and replaced with a native NetBSD partition. The command
183: `fdisk -u sd0` allows to modify interactively the partitions. The modified data
184: will be written on the disk only before exiting and fdisk will request a
185: confirmation before writing, so you can work relaxedly.
186:
187: **Disk geometries**
188:
189: The geometry of the disk reported by fdisk can appear confusing. Dmesg reports
190: 4226725 sectors with 8188/3/172 for C/H/S, but 8188\*3\*172 gives 4225008 and
191: not 4226725. What happens is that most modern disks don't have a fixed geometry
192: and the number of sectors per track changes depending on the cylinder: the only
193: interesting parameter is the number of sectors. The disk reports the C/H/S
194: values but it's a fictitious geometry: the value 172 is the result of the total
195: number of sectors (4226725) divided by 8188 and then by 3.
196:
197: To make things more confusing, the BIOS uses yet another *fake* geometry (C/H/S
198: 524/128/63) which gives a total of 4225536, a value which is a better
199: approximation to the real one than 425008. To partition the disk we will use the
200: BIOS geometry, to maintain compatibility with other operating systems, although
201: we will lose some sectors (4226725 - 4225536 = 1189 sectors = 594 KB).
202:
203: To create the BIOS partitions the command `fdisk -u` must be used; the result is
204: the following:
205:
206: Partition table:
207: 0: sysid 169 (NetBSD)
208: start 63, size 4225473 (2063 MB), flag 0x0
209: beg: cylinder 0, head 1, sector 1
210: end: cylinder 523, head 127, sector 63
211: 1: <UNUSED>
212: 2: <UNUSED>
213: 3: <UNUSED>
214:
215: Now it's time to create the disklabel for the NetBSD partition. The correct
216: steps to do this are:
217:
218: # disklabel sd0 > tempfile
219: # vi tempfile
220: # disklabel -R -r sd0 tempfile
221:
222: If you try to create the disklabel directly with
223:
224: # disklabel -e sd0
225:
226: you get the following message
227:
228: disklabel: ioctl DIOCWDINFO: No disk label on disk;
229: use "disklabel -I" to install initial label
230:
231: because the disklabel does not yet exist on the disk.
232:
233: Now we create some disklabel partitions, editing the `tempfile` as already
234: explained. The result is:
235:
236: # size offset fstype [fsize bsize cpg]
237: a: 2048004 63 4.2BSD 1024 8192 16 # (Cyl. 0*- 3969*)
238: c: 4226662 63 unused 0 0 # (Cyl. 0*- 8191*)
239: d: 4226725 0 unused 0 0 # (Cyl. 0 - 8191*)
240: e: 2178658 2048067 4.2BSD 1024 8192 16 # (Cyl. 3969*- 8191*)
241:
242: *Note*: When the disklabel has been created it is possible to optimize it
243: studying the output of the command `newfs -N /dev/rsd0a`, which warns about
244: the existence of unallocated sectors at the end of a disklabel partition. The
245: values reported by newfs can be used to adjust the sizes of the partitions with
246: an iterative process.
247:
248: The final operation is the creation of the file systems for the newly defined
249: partitions (`a:` and `e:`).
250:
251: # newfs /dev/rsd0a
252: # newfs /dev/rsd0e
253:
254: The disk is now ready for usage, and the two partitions can be mounted. For
255: example:
256:
257: # mount /dev/sd0a /mnt
258:
259: If this succeeds, you may want to put an entry for the partition into
260: `/etc/fstab`.
261:
262: ## How to rebuild the devices in /dev
263:
264: First shutdown to single user, partitions still mounted `rw` (read-write); You
265: can do that by just typing `shutdown now` while you are in multi user mode, or
266: reboot with the `-s` option and make `/` and `/dev` read-writable by doing.
267:
268: # mount -u /
269: # mount -u /dev
270:
271: Then:
272:
273: # mkdir /newdev
274: # cd /newdev
275: # cp /dev/MAKEDEV* .
276: # sh ./MAKEDEV all
277: # cd /
278: # mv dev olddev
279: # mv newdev dev
280: # rm -r olddev
281:
282: Or if you fetched all the sources in `/usr/src`:
283:
284: # mkdir /newdev
285: # cd /newdev
286: # cp /usr/src/etc/MAKEDEV.local .
287: # ( cd /usr/src/etc ; make MAKEDEV )
288: # cp /usr/src/etc/obj*/MAKEDEV .
289: # sh ./MAKEDEV all
290: # cd /
291: # mv dev olddev; mv newdev dev
292: # rm -r olddev
293:
294: You can determine $arch by
295:
296: # uname -m
297:
298: or
299:
300: # sysctl hw.machine_arch
301:
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