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from the man command:

Reformatting dmidecode(8), please wait... DMIDECODE(8) DMIDECODE(8)


      dmidecode - DMI table decoder

Note: In vSphere 5.x this command no longer exists and you have to use




      dmidecode [OPTIONS]


dmidecode is a tool for dumping a computerâs DMI (some say SMBIOS) table contents in a human-readable format. This table contains a description of the systemâs hardware components, as well as other useful pieces of information such as serial numbers and BIOS revision. Thanks to this table, you can retrieve this information without having to probe for the actual hardware. While this is a good point in terms of report speed and safeness, this also makes the presented information possibly unreliable.

The DMI table doesnât only describe what the system is currently made of, it also can report the possible evolutions (such as the fastest supported CPU or the maximal amount of memory supported).

SMBIOS stands for System Management BIOS, while DMI stands for Desktop Management Interface. Both standards are tightly related and developed by the DMTF (Desktop Management Task Force).

As you run it, dmidecode will try to locate the DMI table. If it succeeds, it will then parse this table and display a list of records like this one:

      Handle 0x0002
          DMI type 2, 8 bytes.
          Base Board Information
              Manufacturer: Intel
              Product Name: C440GX+
              Version: 727281-001
              Serial Number: INCY92700942

Each record has:

  • A handle. This is a unique identifier, which allows records to reference each other. For example, processor records usually reference cache memory records using their handles.
  • A type. The SMBIOS specification defines different types of elements a computer can be made of. In this example, the type is 2, which means that the record contains "Base Board Information".
  • A size. Each record has a 4-byte header (2 for the handle, 1 for the type, 1 for the size), the rest is used by the record data. This value doesn't take text strings into account (these are placed at the end of the record), so the actual length of the record may be (and is often) greater than the displayed value.
  • Decoded values. The information presented of course depends on the type of record. Here, we learn about the boardâs manufacturer, model, version and serial number.


      -d, --dev-mem FILE
             Read memory from device FILE (default: /dev/mem)
      -q, --quiet
             Be less verbose. Unknown, inactive and OEM-specific entries  are
             not displayed. Meta-data and handle references are hidden. Mutuâ
             ally exclusive with --dump.
      -s, --string KEYWORD
             Only display the value of the DMI string identified by  KEYWORD.
             KEYWORD  must be a keyword from the following list: bios-vendor,
             bios-version,  bios-release-date,  system-manufacturer,  system-
             product-name,  system-version,  system-serial-number, baseboard-
             manufacturer, baseboard-product-name,  baseboard-version,  baseâ
             board-serial-number,  baseboard-asset-tag, chassis-manufacturer,
             chassis-version, chassis-serial-number, chassis-asset-tag,  proâ
             cessor-manufacturer,  processor-version.   Each  keyword  correâ
             sponds to a given DMI type and a given offset within this  entry
             type.   Not all strings may be meaningful or even defined on all
             systems. Some keywords may return more than one result  on  some
             systems  (e.g.   processor-version on a multi-processor system).
             If KEYWORD is not provided or not valid, a  list  of  all  valid
             keywords  is  printed  and  dmidecode exits with an error.  This
             option cannot be used  more  than  once,  and  implies  --quiet.
             Mutually exclusive with --type and --dump.
      -t, --type TYPE
             Only  display the entries of type TYPE. TYPE can be either a DMI
             type number, or a comma-separated list of  type  numbers,  or  a
             keyword  from the following list: bios, system, baseboard, chasâ
             sis, processor, memory, cache, connector, slot. Refer to the DMI
             TYPES  section  below  for details.  If this option is used more
             than once, the set of displayed entries will be the union of all
             the  given  types.  If TYPE is not provided or not valid, a list
             of all valid keywords is printed and  dmidecode  exits  with  an
             error.  Mutually exclusive with --string.
      -u, --dump
             Do  not  decode  the entries, dump their contents as hexadecimal
             instead.  Note that this is still a text output, no binary  data
             will  be thrown upon you. The strings attached to each entry are
             displayed as both hexadecimal and ASCII. This option  is  mainly
             useful  for  debugging.   Mutually  exclusive  with  --quiet and
      -h, --help
             Display usage information and exit
      -V, --version
             Display the version and exit


      The SMBIOS specification defines the following DMI types:
      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
      Additionally, type 126 is used for disabled entries,  type  127  is  an
      end-of-table  marker,  and  types 128 to 255 are for OEM-specific data.
      dmidecode will display these entries  by  default,  but  cannot  decode
      Keywords can be used instead of type numbers with --type.  Each keyword
      is equivalent to a list of type numbers:
      Keyword     Types
      bios        0, 13
      system      1, 12, 15, 23, 32
      baseboard   2, 10
      chassis     3
      processor   4
      memory      5, 6, 16, 17
      cache       7
      connector   8
      slot        9
      Keywords are matched case-insensitively. The  following  command  lines
      are equivalent:
  • dmidecode --type 0 --type 13
  • dmidecode --type 0,13
  • dmidecode --type 0 --type 13
  • dmidecode --type 0,13
  • dmidecode --type bios
  • dmidecode --type BIOS




      More often than not, information contained in the DMI tables is inaccuâ
      rate, incomplete or simply wrong.


      Alan Cox, Jean Delvare


      biosdecode(8), mem(4), ownership(8), vpddecode(8)

dmidecode August 2005 DMIDECODE(8)

Example output

Here's a snippet of output on an ESX host when displaying memory info:

Handle 0x0028
       DMI type 17, 27 bytes.
       Memory Device
               Array Handle: 0x0025
               Error Information Handle: No Error
               Total Width: 76 bits
               Data Width: 72 bits
               Size: 1024 MB
               Form Factor: DIMM
               Set: 1
               Locator: DIMM 2A
               Bank Locator: Bank0 Bank1
               Type: DDR
               Type Detail: Synchronous
               Speed: 266 MHz (3.8 ns)
               Manufacturer: Not Specified
               Serial Number: Not Specified
               Asset Tag: Not Specified
               Part Number: Not Specified