Essential System Administration Pocket Reference

Devices and Device Files

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dmesg	dmesg	Not available under AIX
	Display boot and other system messages. Devices are listed within the messages as the devices are detected.

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Vendor-specific device listing commands

AIX:	lscfg lsdev -C -s scsi lscfg -v -l device lsattr -E -H -l device	List all devices. List all SCSI devices. Display device details. Display device attributes.
FreeBSD:	pciconf -l -v camcontrol devlist usbdevs	List PCI devices. List SCSI devices. List USB devices.
HP-UX:	ioscan -f -n ioscan -f -n -C disk	Display detailed device listing. Limit to device class.
Linux:	lsdev scsiinfo -l lspci lsusb	List major devices. List SCSI devices. List PCI devices. List USB devices.
Solaris:	getdev getdev type=class devattr -v device	List devices. Limit to device class. Display device detail.

Special File Formats

In all cases, the optional r in special filenames refers to the character device (i.e., raw access mode), and the other name refers to the block device.

Disk partition special filenames

AIX:	/dev/hdiskn (refers to entire disk)
	n is the disk number. Example: /dev/hdisk1
FreeBSD:	/dev/[r]ppnsmx (often shortened to /dev/[r]ppnx) pp is a device-specific prefix (e.g., ad or wd for IDE disks, da for SCSI), n is the disk number, m is the slice number (physical partition), and x is the partition letter. Example: /dev/da1s1a
HP-UX:	/dev/[r]dsk/cktidn k is the controller number, i is the SCSI ID, and n is the disk number. Example: /dev/dsk/c0t4d1
Linux:	/dev/[sd|hd]ym The sd/hd prefix refers to SCSI/IDE disks, respectively, y is the disk letter (where a refers to the first disk, etc.), and m is the physical partition number. Example: /dev/ hda1
Solaris:	/dev/[r]dsk/cktid0sm k is the controller number, i is the SCSI ID, and m is the physical partition number. Example: /dev/dsk/c0t4d0s2

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CD-ROM device special filenames

AIX:	/dev/cd0	HP-UX:	/dev/dsk/cktid0
Linux:	/dev/cdrom	Solaris:	/dev/dsk/c0tid0s02
FreeBSD:	/dev/cd0c (SCSI), /dev/acd0c (ATAPI)

For HP-UX and Solaris, k and i have the same meanings in special filenames for both disks and CD-ROMs.

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Floppy disk special filenames

AIX:	/dev/fd0	FreeBSD:	/dev/fd0
HP-UX:	/dev/dsk/c0t1d0	Linux:	/dev/fd0
Solaris:	/dev/diskette

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Network interface names

The following list indicates the first network interface. Additional interfaces will have higher numbers (e.g., eth1).

AIX:	en0	FreeBSD:	xl0, de0 (and others)
HP-UX:	lan0	Linux:	eth0
Solaris:	hme0, dnet0, eri0, le0 (and others)

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Tape special filenames

k is the drive number, and n means “no rewind” in all cases.

AIX:	/dev/rmtk[.m] m is a suffix indicating rewind, retensioning, and density settings (see the rmt(4) man page). The default is rewind, no retension, and low density.
FreeBSD:	/dev/[n]rastk and /dev/[e|n]rsak e means “eject tape on close.”
HP-UX:	/dev/rmt/citjd0TYPE[b][n] i is the controller number, j is the SCSI ID, b says to use BSD-style error control, and TYPE is a keyword that indicates the tape type and/or density (e.g., BEST, DDS). /dev/rmt often contains links between these names and simpler ones (e.g., 0m linked to c0t3d0BEST).
Linux:	/dev/[n]stk[x] x indicates the density selection: l, m, and a for low, medium, and autoselect, respectively.
Solaris:	/dev/rmt/k[x][b][n][c] b says to use BSD-style error control, x indicates the density (l, m, and h for low, medium, and high, respectively), and c says to use hardware compression.

Default tape drive

AIX:	/dev/rmt0	FreeBSD:	/dev/rsa0
HP-UX:	/dev/rmt/0m	Linux:	/dev/st0
Solaris:	/dev/rmt/0

Modifying tape drive settings under AIX

lsattr -E -H -l device

Display attributes to the specified tape drive.

chdev -l rmtn -a block_size=bytes -a compress=yes|no \ -a ret=yes|no

Change settings of the specified tape drive.

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Serial line special files

The following table gives the form for the first device of each type:

	Serial line	Dial-out form	Slave pseudo terminal
AIX:	/dev/tty0	/dev/tty0	/dev/pts/0
FreeBSD:	/dev/ttyd0	/dev/cuaa0	/dev/ttyp0
HP-UX:	/dev/tty0p0	/dev/cua0p0	/dev/ttyd0p0, /dev/pts/0
Linux:	/dev/ttyS0	/dev/ttyS0	/dev/ttyp0
Solaris:	/dev/term/a	/dev/cua/0	/dev/pts/0

System console: /dev/console

System console device. On AIX systems, the console device in terminal mode is /dev/lft0.

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Printer special filenames

First parallel port devices:

AIX:	/dev/lp0	FreeBSD:	/dev/lpt0
HP-UX:	/dev/lp	Solaris:	/dev/ecpp0
Linux:	/dev/parport0 (usually mapped to /dev/lp0)

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USB device special files

The following list shows the first file of each type.

Mouse

FreeBSD:	/dev/ums0	Solaris:	/dev/usbms
Linux:	/dev/input/mouse0 and /dev/input/mice

Zip drive

FreeBSD:	/dev/da0s4	Linux:	/dev/sda4
Solaris:	/dev/dsk/c1t0d0s0:c

Printer

FreeBSD:	/dev/ulpt0	Linux:	/dev/usblp0
Solaris:	/dev/usbprn0

Other devices found on some systems

/dev/null

Null device (discards all output; reads return 0 bytes).

/dev/zero

Returns a zero-filler buffer.

/dev/random

Random number generator.