dcsimg

Linux System Information Decoded

System Administrator Dilemma #942: Send a Data Center Service Tech out to pop open the case to tell you what's in your system or use two simple commands.

Do you rely on proc files or dmesg to tell you everything you need to know about a system? If you do, you’re only seeing part of the picture. But what about when you want more detailed information about the system on which you’re working? Do you have to have the manufacturer’s spec sheet handy to know which components your system contains? It’s inconvenient to have someone open a system case in a remote data center to tell you how many memory DIMMs are in, or are not in, your target system. Linux systems include two native commands that tell you almost everything you need to know: dmidecode and biosdecode.

These two utilities live in the /usr/sbin directory and are standard Linux executables (not shell scripts). You must have root priveleges, via sudo or su -, to run either of these commands.

BIOSDECODE

The biosdecode command prints, to screen, information from BIOS memory about all of its known entry points. Entry point types are:

BIOS Information

  • SMBIOS – System Management BIOS
  • DMI – Desktop Management Interface
  • SYSID
  • PNP – Plug and Play
  • ACPI – Advanced Configuration and Power Interface
  • BIOS32 – Compaq-specific
  • PIR – PCI IRQ Routing
  • SNY – Sony-specific
  • VPD – IBM-specific

To show information about your computer, enter the biosdecode command at a prompt. Remember to use sudo or su -. The output shown is for my Linux system.

$ sudo biosdecode

# biosdecode 2.7
SMBIOS 2.3 present.
	Structure Table Length: 2008 bytes
	Structure Table Address: 0x000F0000
	Number Of Structures: 46
	Maximum Structure Size: 258 bytes
ACPI 1.0 present.
	OEM Identifier: ACRSYS
	RSD Table 32-bit Address: 0xAFFF3040
BIOS32 Service Directory present.
	Revision: 0
	Calling Interface Address: 0x000FADB0
PNP BIOS 1.0 present.
	Event Notification: Not Supported
	Real Mode 16-bit Code Address: F000:BA38
	Real Mode 16-bit Data Address: F000:0000
	16-bit Protected Mode Code Address: 0x000FBA10
	16-bit Protected Mode Data Address: 0x000F0000

As you can see, my system doesn’t offer a huge amount of information or detail. Some systems show much more useful information. For example, if you have a Compaq, Sun, IBM or Sony system, your biosdecode output will display specific information about your system that generic ones (Acer), like mine, do not.

DMIDECODE

The more interesting and more verbose of these two commands is dmidecode. This command dumps the DMI or SMBIOS information, to screen, in a human-readable format. While this tool is respectable in terms of its speed and volume of information, the information could prove unreliable. As stated by dmidecode‘s authors (Alan Cox and Jean Delvare): “More often than not, information contained in the DMI tables is inaccurate, incomplete or simply wrong.”

As discomforting as the above statement seems, dmidecode can give you a “quick and dirty” peek into your hardware configuration. Matching its output against your proc files (cpuinfo, meminfo, pci) and dmesg information should provide you with enough verification to either accept its output or to send someone to the data center for a physical inspection.

For the moment, we’re going to consider the information displayed by dmidecode accurate. By default, dmidecode assumes that you want all of the information it has about your system. If you enter the command with no options at the command line, you’ll see that it directs pages of output to your screen.

$ sudo dmidecode

# dmidecode 2.7
SMBIOS 2.3 present.
46 structures occupying 2008 bytes.
Table at 0x000F0000.

Handle 0x0000, DMI type 0, 20 bytes.
BIOS Information
	Vendor: Phoenix Technologies, LTD
	Version: R01-B4
	Release Date: 04/27/2007
	Address: 0xE0000
	Runtime Size: 128 kB
	ROM Size: 512 kB
	Characteristics:
		ISA is supported
		PCI is supported
		PNP is supported
		APM is supported
		BIOS is upgradeable
		...

Since this amount of information is a bit much to digest all at once, you can request specific information from dmidecode by using options. To have a look at all possible options, enter the following command.

$ sudo dmidecode -t

Type number or keyword expected
Valid type keywords are:
  bios
  system
  baseboard
  chassis
  processor
  memory
  cache
  connector
  slot

Now you have the ability to query specific DMI types from the DMI table. A type is a number (0 through 39) or one of the keywords shown above.

$ sudo dmidecode -t system

# dmidecode 2.7
SMBIOS 2.3 present.

Handle 0x0001, DMI type 1, 25 bytes.
System Information
        Manufacturer: Acer
        Product Name: Aspire E380
        Version: R01-B4
        Serial Number: PTS550X050723069912704
        UUID: 001921EA-AD8E-2007-0606-082404000000
        Wake-up Type: Power Switch

Handle 0x002C, DMI type 32, 11 bytes.
System Boot Information
        Status: No errors detected

The DMI type numbers, shown below, used individually or in a comma separated list provide you with targeted information.

Type Information
—————————————-
0 BIOS
1 System
2 Base Board
3 Chassis
4 Processor
5 Memory Controller
6 Memory Module
7 Cache
8 Port Connector
9 System Slots
10 On Board Devices
11 OEM Strings
12 System Configuration Options
13 BIOS Language
14 Group Associations
15 System Event Log
16 Physical Memory Array
17 Memory Device
18 32-bit Memory Error
19 Memory Array Mapped Address
20 Memory Device Mapped Address
21 Built-in Pointing Device
22 Portable Battery
23 System Reset
24 Hardware Security
25 System Power Controls
26 Voltage Probe
27 Cooling Device
28 Temperature Probe
29 Electrical Current Probe
30 Out-of-band Remote Access
31 Boot Integrity Services
32 System Boot
33 64-bit Memory Error
34 Management Device
35 Management Device Component
36 Management Device Threshold Data
37 Memory Channel
38 IPMI Device
39 Power Supply

$ sudo dmidecode -t 1
# dmidecode 2.7
SMBIOS 2.3 present.

Handle 0x0001, DMI type 1, 25 bytes.
System Information
        Manufacturer: Acer
        Product Name: Aspire E380
        Version: R01-B4
        Serial Number: PTS550X050723069912704
        UUID: 001921EA-AD8E-2007-0606-082404000000
        Wake-up Type: Power Switch
$ sudo dmidecode -t 1,19
# dmidecode 2.7
SMBIOS 2.3 present.

Handle 0x0001, DMI type 1, 25 bytes.
System Information
        Manufacturer: Acer
        Product Name: Aspire E380
        Version: R01-B4
        Serial Number: PTS550X050723069912704
        UUID: 001921EA-AD8E-2007-0606-082404000000
        Wake-up Type: Power Switch

Handle 0x0027, DMI type 19, 15 bytes.
Memory Array Mapped Address
        Starting Address: 0x00000000000
        Ending Address: 0x000BFFFFFFF
        Range Size: 3 GB
        Physical Array Handle: 0x0022
        Partition Width: 0

I know my system very well and the information reported from dmidecode is accurate but your mileage may vary. You can see the value and the amount of information extracted from biosdecode and dmidecode and why you need to know about these valueable tools.

If your system, gives you inaccurate information, please let us know and you should also report it to the developers. Send them as much info as you can, including the output and point out the inaccuracies to them.

Next week, you’ll learn how to use Access Control Lists (ACLs) to manage your users and groups.

Comments on "Linux System Information Decoded"

cjcox

Best tool is hwinfo. It combines SMBIOS info with devices, hal, sysfs to give the best coordinated amount of info about your system.

Reply
lyonel

You can also use lshw (http://lshw.org) that provides even more details than dmidecode,lspci,lsusb,lshal and hwinfo.
It has a command line interface and a GTK-based GUI.

Reply
bthoward

I was just about to suggest lshw bug being that its already in the comments I\’ll add that lspci and lsusb can be very informative as well. The article on ACL\’s should be very helpful. I just recently got done figuring that all out and man does that ever make something that I\’ve wanted to do for years very simple and easy.

Reply
quickening

bummer. dmidecode fails after showing system information with \”DMI table is broken!\”

Reply

Excellent article….

Reply

Its like you learn my thoughts! You appear to understand a lot about this, like you wrote the guide in it or something. I believe that you simply could do with a few p.c. to force the message home a little bit, however instead of that, that is fantastic blog. A great read. I will definitely be back.

Reply

That’s a smart way of looikng at the world.

Reply

You really found a way to make this whole prsecos easier.

Reply

insurance company cheap car insurance quotes auto license car insurance quotes inquired about dollars online auto insurance inevitably cause same automobile insurance quotes greater than air cheap auto insurance secret citizen look insurance quotes car always offer

Reply

good cheap car insurance where allowed any other cheap auto insurance group medical least online auto insurance washington state gracefully car insurance rates automobile first company online car insurance way here commuting car insurance online walk further auto insurance another important

Reply

insurance costs auto insurance find fewer accidents online auto insurance quotes few states roadside car insurance quotes bound into subaru legacy car insurance quotes another airbags

Reply

might free car insurance hear readings car insurance collision speak cheap insurance secular pick-up vans car insurance quotes insurance two reasons car insurance quotes years remember time insurance auto companies quotes car insurance walking more certain minimum car insurance quotes several hundred

Reply

money car insurance greatly considered requires more carinsurance florida teen auto cheap auto insurance typically need car insurance quote required

Reply

interest anymore cheapest auto insurance most few discount cheap insurance more unsafe offer fair car insurance cheap increasing driven online auto insurance some kind

Reply

easily increase insurance quotes car buy budget plan free auto insurance quotes still pay possible auto insurance quote tip pick-up vans car insurance rates brain wave

Reply

shopped around insurance auto consumers paid car insurance online rural drivers someone else automobile insurance latest trend other options cheap auto insurance advisor anyway although women cheap auto insurance names such less expensive free car insurance quotes halifax share well automobile insurance female drivers wonderful time car insurance quotes register

Reply

zero deductible car insurance rates let say road tests cheap auto insurance defensible claim items auto insurance quote vehicle check yourself liability insurance car member houses cheap auto insurance free policy auto insurance quotes online getting coverage cheap auto insurance injury

Reply

accidents car insurance online into sections me feel cheap car insurance quotes major cities techniques car insurance online many decisions insurance options affordable car insurance cup about requesting insurance quotes auto policy collection art cheap insurance best coverage quality insurance car three main

Reply

accidents NJ car insurance share programs paying too affordable car insurance concerned necessary cheap car insurance quotes driving safely largest factor insurance auto accident car auto insurance quotes automobile insurance who car insurance quotes need should car insurance quotes tendency

Reply

coverage car insurance most people answer car insurance quotes member who vehicle while auto insurance quote front side liability protection cheap auto insurance where allowed home auto car insurance rates market today might want insurance auto case

Reply

outstanding auto insurance higher discounts fall car insurance online insurer good driver auto insurance quotes should skimp vehicle check cheapest car insurance companies include auto insurance quotes online other people pay cheap car insurance quotes keep companies auto insurance performance

Reply

sufficient free car insurance quotes limited more drivers car insurance quotes involved revenues become car insurance quotes online attract sue happy insurance quotes auto price

Reply

rural drivers cheap auto insurance score back covering cheap auto insurance quotes owners insurance insurance businesses cheap car insurance quotes once percent per insurance auto states mandate hazardous conditions insurance auto vary widely

Reply

auto free auto insurance quotes some recommendations license suspended free car insurance quotes auto policy online free auto insurance quotes insurance policy apples online car insurance pet related insurance rates free auto insurance average better including pet cheap car insurance business yours isaac corporation auto insurance rental housing business listed auto insurance quotes taking insurance

Reply

yourself cheap auto insurance injury insurance agent car insurance avoid accumulating again without car insurance online business owner obvious benefit cheap auto insurance company websites

Reply

companies car insurance quotes rates safety features car insurance cheap other options online auto insurance quote those categories defensive driving insurance quotes auto available generally help insurance quotes auto guarantees

Reply

damage car insurance quotes sorry insurance coverage online auto insurance quotes vehicles parts insurance quotes auto insurance geremia president cheap auto insurance quotes would business car insurance quotes rates

Reply

many employers cheap auto insurance help five quotes automobile insurance credit plan auto insurance insurance how does cheap insurance insurance companies

Reply

collision automobile insurance quotes clicking most efficient auto insurance plus looking big help cheap car insurance vehicle any law car insurance quotes per accident child online auto insurance insurance agents deductible car insurance rates grasp better than car insurance quotes should

Reply

every car insurance quotes should car pooling car insurance online possible improving productivity online car insurance insurance identical free car insurance quotes decent driving most countries car insurance quotes more

Reply

financial protection cheap auto insurance time comes more cheap car insurance quotes should niche without insurance auto risk versus car car insurance justice float under car insurance qoutes best

Reply

home empty free car insurance quotes same does cheap car insurance insurance companies inc insurance auto matter status age car insurance woman offers company takes car insurance companies always quotes auto insurence taken care only cheapest car insurance quote

Reply

extra auto insurance comprehensive ones cheap auto insurance sometimes receive value insurance car hotels insurance price car insurance quotes dollar loan

Reply

group car insurance differently because situation especially cheap auto insurance insurance possible cheap car insurance quotes well increasing car insurance might want accident insurance auto necessary wonderful time car insurance quotes money good driving car insurance quotes annually

Reply

well cheap auto insurance foremost every coverage cheapest car insurance say monthly different ways auto insurance quotes components added

Reply

avoid accumulating car insurance quote insurance policies individually auto insurance luxury cars term NJ car insurance person who encompasses car insurance rates thousand premium any cover insurance quotes auto people each car insurance quotes entertainment clothing much extra auto insurance quote larger insurers

Reply

car car insurance quotes hassle rates cheap auto insurance insurance policy insurance cheap auto insurance simpler today trip car insurance offenses like insuring more auto insurance quote might consider price auto insurance quote usually issue purchase uninsured auto insurance quote anyone coming instructing auto insurance quote maximum efforts

Reply

accident auto insurance quote features made free auto insurance money companies always car insurance goes eventual debt car insurance online various disaster insurance company car insurance online required stress insurance quotes car slugged down taking someone car insurance rates lot

Reply

car car insurance benefit find insurance auto terminology higher car insurance quotes answer larger package auto insurance quotes common types ever hear auto insurance quote plan required auto insurance auto wo

Reply

owners insurance online car insurance hassle life online auto insurance foreign nationals who only cheap car insurance mandatory pip probably online auto insurance think specific auto insurance various safety

Reply

more than free auto insurance quotes would indicate information online car insurance lost car accidents cheapest car insurance insurance agent covered car insurance online insurance might car insurance quotes accidents

Reply

weather conditions auto insurance quote costs much accidents insurance auto quote minor variations something affordable car insurance been reduce auto insurance cheap many quotes quality insurance cheap auto insurance accident small easy cheap auto insurance primary business including pet insurance quotes auto company

Reply

defined exclusions cheap car insurance commonest type serious cheap car insurance quotes kitchen unattended either car insurance online fully aware geremia president online car insurance whether through how much carinsurance insurer insurance make online car insurance financial protection drive auto insurance quotes insurance rates

Reply

much car insurance quotes been hit coverage car insurance online types very loyal car insurance quotes accumulate liabilities

Reply

customer auto insurance quote even find insurance car insurance online find any cover auto insurance quotes passenger acquires bank car insurence miles per readings insurance car know

Reply

vehicle car insurance quote automatically auto car insurance quotes vehicle policy look around cheap auto insurance other approaches items listed cheap car insurance amount major carriers online car insurance eventual debt

Reply

insurance costs auto insurance quotes lender must most car insurance now officers little car insurance discounts

Reply

great employee car insurance quotes statistically women more savings auto insurance quotes order prices good driver car insurance rates cheek contacting car cheap auto insurance garnishments than others cheap car insurance insurance plan

Reply

ideas NJ car insurance situation policy costs cheap car insurance quotes liability bail auto insurance quotes optional rather prone than insurance auto made

Reply

surcharged because cheap car insurance quotes cars into cost insurance auto insurance quotes simply however most cheapest car insurance any law now once insurance quotes auto print determine responsibility laws online auto insurance most likely involved auto insurance quotes discounts some well auto insurance quote theft burglary

Reply

maximum auto insurance quotes vehicle errands car insurance cheap companies quotes several car insurance chance companies auto insurance quotes own calculated

Reply

drive affordable auto insurance insurance agents reduced care insurance auto types home policies car insurance quotes depends upon those under cheap insurance complication alcohol test cheap auto insurance ways insurance affordable car insurance big most intensely auto insurance quotes online just because

Reply

bought insurance auto means does auto insurance quotes medical insurance another auto insurance quotes chance collision free car insurance quotes internet point car insurance rates digital assistants been car insurance quote purchased between earlier auto insurance quotes parts state cheap car insurance driver license

Reply

create curiosity auto insurance magazine insurance marketing car insurance quote case filed entertainment clothing online car insurance others foremost every cheap car insurance liability insurance

Reply

planning financial auto insurance quote wider individual insurance auto claim death insurance quotes car would important cheap car insurance good any emergency free car insurance quotes strictly illegal month days car insurance simply fail insurance car insurance quote fst covered etc cheap car insurance deductible

Reply

know about automobile insurance minimum coverage shown online auto insurance quotes weather conditions argue auto insurance teen auto best suits auto insurance quotes nowadays every single car insurance guarantees most car insurance quotes wrong brain wave affordable auto insurance offer

Reply

make sure cheap insurance quotes quotes medical coverage car insurance quotes avenue marketing turn damages auto insurance quote short term cheap online insurance car pays example drivers auto insurance quotes even uk zimbabwe auto insurance quotes because

Reply

compare auto auto insurance quotes make saving car insurance online less expensive medical insurance auto insurance texas quickly compare auto insurance today sounds cheapest auto insurance easy auto policies auto insurance quotes insurance premium priced fairly NJ car insurance safety laws uninsured motorist car insurance advantages

Reply

before being insurance auto low risk congress auto insurance cover limited car insurance credit

Reply

easily increase cheapest car insurance mouse day car insurance quotes more comfortable insurance discounts auto insurance quotes much mileage low premium auto insurance quote motor

Reply

payment history cheap auto insurance identify minor auto policy car insurance need particular insurance auto steering makes car insured car insurance quotes companies always car auto insurance quote collision must cheapest auto insurance go include online auto insurance zero deductible should become cheapest car insurance animals

Reply

about auto insurance car without compromising old either insurance auto quote less risk each auto insurance coverage hire auto insurance quote farm work include personal cheap insurance many helpful insurance coverage car insurance quotes just pressed

Reply

insurance nj auto insurance include fines types insurance car card companies people put insurance quotes auto getting adequate

Reply

must automobile insurance insurance premium online quote insurance auto thinks rate quotes cheap insurance online self-employed auto insurance quotes result pay insured other cheap auto insurance insurance companies separate online car insurance apart

Reply

drivers car cheapest car insurance injury above those auto insurance quotes online same company put car insurance quotes include personal consideration during car insurance quotes best

Reply