Device Files in HP-UX 11i
What could be more confusing in the UNIX world than device files? Fortunately, in HP-UX, device files for workstations and servers are nearly identical, so if you learn one, your knowledge applies to the other. In this section, I cover:
The structure of device files
Some commands associated with helping you work with device files
Some examples of creating device files
A device file provides the HP-UX kernel with important information about a specific device. The HP-UX kernel needs to know a lot about a device before Input/Output operations can be performed. With HP-UX 11i, the device file naming convention is the same for workstations and server systems. Device files are in the /dev directory. There may also be a subdirectory under /dev used to further categorize the device files. Examples of a subdirectories are /dev/dsk, where disk device files are usually located, and /dev/rmt, where tape drive device files are located. Figure 5-1 shows the HP-UX 11i device file-naming convention.
Figure 5-1. HP-UX 11i Device File Naming Convention
There are a number of commands that you can use as you go about creating device files. The ioscan command is the first of these. Some of the examples in this section were used in Chapter 3, when building a kernel was covered. The following is an ioscan output of the same workstation for which sysdef was run when describing how a kernel is created in Chapter 3. (Using -f with ioscan would have created a full listing; you should try it with and without -f.) I included four ioscan outputs so you could see examples from a variety of different systems. The last listing is from a large V-Class system used in some of the examples in Chapter 8, where disks and file systems are covered.
(on workstation)
$ /usr/sbin/ioscan
H/W Path Class Description
============================================================
bc
1 graphics Graphics
2 ba
2/0 unknown
2/0/1 ext_bus Built-in SCSI
2/0/1.1 target
2/0/1.1.0 disk HP C2247
2/0/1.2 target
2/0/1.2.0 disk TOSHIBA CD-ROM XM-3301TA
2/0/1.6 target
2/0/1.6.0 disk HP C2247
2/0/2 lan Built-in LAN
2/0/4 tty Built-in RS-232C
2/0/6 ext_bus Built-in Parallel Interface
2/0/8 audio Built-in Audio
2/0/10 pc Built-in Floppy Drive
2/0/10.1 floppy HP_PC_FDC_FLOPPY
2/0/11 ps2 Built-in Keyboard
8 processor Processor
9 memory Memory
The following is an ioscan output from a server system. Note the four processors shown in this output.
(on server)
$ /usr/sbin/ioscan
H/W Path Class Description
============================================================
bc
8 bc I/O Adapter
10 bc I/O Adapter
10/0 ext_bus GSC built-in Fast/Wide SCSI
10/0.3 target
10/0.3.0 disk HP C2490WD
10/0.4 target
10/0.4.0 disk HP C2490WD
10/0.5 target
10/0.5.0 disk HP C2490WD
10/0.6 target
10/0.6.0 disk HP C2490WD
10/4 bc Bus Converter
10/4/0 tty MUX
10/12 ba Core I/O Adapter
10/12/0 ext_bus Built-in Parallel Interface
10/12/5 ext_bus Built-in SCSI
10/12/5.0 target
10/12/5.0.0 tape HP HP35480A
10/12/5.2 target
10/12/5.2.0 disk TOSHIBA CD-ROM XM-4101TA
10/12/6 lan Built-in LAN
10//12/7 ps2 Built-in Keyboard/Mouse
32 processor Processor
34 processor Processor
36 processor Processor
38 processor Processor
49 memory Memory
The next command that helps you when creating device files is lsdev. lsdev lists the drivers configured into your system. When adding a device file, you need to have the driver for the device configured into the system. You can use the manual kernel configuration process covered earlier to add a driver to the kernel. There are columns for the major number for a character device and block device, the driver name, and the class of the driver. The major number, character device, and other parameters are defined later. Here is an example of running lsdev on the same workstation on which ioscan was run:
(on workstation)
$ /usr/sbin/lsdev
Character Block Driver Class
0 -1 cn pseudo
1 -1 ansio0 tty
3 -1 mm pseudo
16 -1 ptym ptym
17 -1 ptys ptys
24 -1 hil hil
27 -1 dmem pseudo
46 -1 netdiag1 unknown
52 -1 lan2 lan
64 64 lv lvm
66 -1 audio audio
69 -1 dev_config pseudo
72 -1 clone pseudo
73 -1 strlog pseudo
74 -1 sad pseudo
75 -1 telm strtelm
76 -1 tels strtels
77 -1 tlctls pseudo
78 -1 tlcots pseudo
79 -1 tlcotsod pseudo
114 -1 ip pseudo
115 -1 arp pseudo
116 -1 echo pseudo
119 -1 dlpi pseudo
130 -1 rawip pseudo
136 -1 tcp pseudo
137 -1 udp pseudo
138 -1 stcpmap pseudo
139 -1 nuls pseudo
140 -1 netqa pseudo
141 -1 tun pseudo
142 -1 btlan3 unknown
143 -1 fddi3 unknown
144 -1 fddi0 unknown
145 -1 fcT1_cntl unknown
156 -1 ptm strptym
157 -1 ptm strptys
159 -1 ps2 ps2
164 -1 pipedev unknown
168 -1 beep graf_pseudo
169 -1 fcgsc_lan lan
170 -1 lpr0 unknown
174 -1 framebuf graf_pseudo
183 -1 diag1 diag
188 31 sdisk disk
189 -1 klog pseudo
196 -1 eeprom da
203 -1 sctl ctl
205 -1 stape tape
207 -1 sy pseudo
216 -1 CentIF ext_bus
227 -1 kepd pseudo
229 -1 ite graf_pseudo
232 -1 diag2 diag
Here is an example of running lsdev on the same server on which ioscan was run:
(on server)
$ /usr/sbin/lsdev
Character Block Driver Class
0 -1 cn pseudo
1 -1 asio0 tty
3 -1 mm pseudo
16 -1 ptym ptym
17 -1 ptys ptys
28 -1 diag0 diag
46 -1 netdiag1 unknown
52 -1 lan2 lan
64 64 lv lvm
69 -1 dev_config pseudo
72 -1 clone pseudo
73 -1 strlog pseudo
74 -1 sad pseudo
75 -1 telm strtelm
76 -1 tels strtels
77 -1 tlctls pseudo
78 -1 tlcots pseudo
79 -1 tlcotsod pseudo
114 -1 ip pseudo
116 -1 echo pseudo
119 -1 dlpi pseudo
130 -1 rawip pseudo
136 -1 lpr0 unknown
137 -1 udp pseudo
138 -1 stcpmap pseudo
139 -1 nuls pseudo
140 -1 netqa pseudo
141 -1 tun pseuod
142 -1 btlan3 unknown
143 -1 fddi3 unknown
144 -1 fddi0 unknown
156 -1 ptm strptym
157 -1 ptm strptys
159 -1 ps2 ps2
164 -1 pipedev unknown
168 -1 beep graf_pseudo
174 -1 framebuf graf_pseudo
188 31 sdisk disk
189 -1 klog pseudo
193 -1 mux2 tty
203 -1 sctl ctl
205 -1 stape tape
207 -1 sy pseudo
216 -1 CentIF ext_bus
227 -1 kepd pseudo
229 -1 ite graf_pseudo
From these two lsdev outputs, you can observe some minor differences in the devices. The workstation, for instance, has such classes as audio and floppy, the server has a multiplexer.
You can use ioscan to show the device files for a particular peripheral. Going back to the server that had four disks and a CD-ROM attached to it, you could issue the following ioscan command to see the device files associated with disk:
(on server)
$ /usr/sbin/ioscan -fn -C disk
Class I H/W Path Driver S/W State H/W Type Description
============================================================
disk 0 10/0.3.0 sdisk CLAIMED DEVICE HP C2490WD
/dev/dsk/c0t3d0 /dev/rdsk/c0t3d0
disk 1 10/0.4.0 sdisk CLAIMED DEVICE HP C2490WD
/dev/dsk/c0t4d0 /dev/rdsk/c0t4d0
disk 2 10/0.5.0 sdisk CLAIMED DEVICE HP C2490WD
/dev/dsk/c0t5d0 /dev/rdsk/c0t5d0
disk 3 10/0.6.0 sdisk CLAIMED DEVICE HP C2490WD
/dev/dsk/c0t6d0 /dev/rdsk/c0t6d0
disk 3 10/12/5/2/0 sdisk CLAIMED DEVICE CD-ROM
/dev/dsk/c1t2d0 /dev/rdsk/c1t2d0
You can see from this ioscan all of the device files associated with disk, including the CD-ROM.
You could find out more information about one of these devices with the diskinfo command. Specify the character device you want to know more about, as shown below (using the -v option for verbose provides more detailed information).
$ diskinfo /dev/rdsk/c0t5d0
SCSI describe of /dev/rdsk/c0t5d0
vendor: HP
product id: C2490WD
type: direct access
size: 2082636 bytes
bytes per sector: 512