Dmidecode command reads the system DMI (Desktop Management Interface) table to display hardware and BIOS information of the server. The output of the dmidecode contains several records from the DMI table. This table contains a description of the systems hardware components and also other useful information such as serial number, BIOS revision, etc. As you run it, dmidecode will try to locate the DMI table. If it succeeds, then it will parse this table and display a list of records like this.
The DMI table doesn't only describe what the system is currently made of, it also can report the possible evolution (such as the fastest supported CPU or the maximal amount of memory supported).
This tutorial explains how to use dmidecode to get hardware information on your Linux machine.
1) Get Hardware information on BIOS
To get BIOS version, vendor and other details ,use -t bios option
# dmidecode -t bios
# dmidecode 2.9
SMBIOS 2.31 present.
Handle 0x0000, DMI type 0, 20 bytes
BIOS Information
Vendor: Phoenix Technologies LTD
Version: 6.00
Release Date: 04/10/2007
Address: 0xE7A00
Runtime Size: 99840 bytes
ROM Size: 64 kB
Characteristics:
ISA is supported
PCI is supported
PC Card (PCMCIA) is supported
PNP is supported
APM is supported
BIOS is upgradeable
BIOS shadowing is allowed
ESCD support is available
USB legacy is supported
Smart battery is supported
BIOS boot specification is supported
[root@mailserver ~]#2) Get Hardware information about system
Use -t system to get hardware information about system
# dmidecode -t system
# dmidecode 2.9
SMBIOS 2.31 present.
Handle 0x0001, DMI type 1, 25 bytes
System Information
Manufacturer: VMware, Inc.
Product Name: VMware Virtual Platform
Version: None
Serial Number: VMware-56 4d eb 70 28 36 a8 c0-08 bb 55 cf dc e6 4f 60
UUID: 564DEB70-2836-A8C0-08BB-55CFDCE64F60
Wake-up Type: Power Switch
Handle 0x001C, DMI type 15, 29 bytes
System Event Log
Area Length: 16 bytes
Header Start Offset: 0x0000
Header Length: 16 bytes
Data Start Offset: 0x0010
Access Method: General-purpose non-volatile data functions
Access Address: 0x0000
Status: Invalid, Full
Change Token: 0x00000036
Header Format: Type 1
Supported Log Type Descriptors: 3
Descriptor 1: POST error
Data Format 1: POST results bitmap
Descriptor 2: Single-bit ECC memory error
Data Format 2: Multiple-event
Descriptor 3: Multi-bit ECC memory error
Data Format 3: Multiple-event
Handle 0x0026, DMI type 23, 13 bytes
System Reset
Status: Enabled
Watchdog Timer: Present
Boot Option: Do Not Reboot
Boot Option On Limit: Do Not Reboot
Reset Count: Unknown
Reset Limit: Unknown
Timer Interval: Unknown
Timeout: Unknown
Handle 0x0029, DMI type 32, 20 bytes
System Boot Information
Status:
#3) Hardware information about baseboard
Use -t baseboard to get information about baseboard
# dmidecode -t baseboard
# dmidecode 2.9
SMBIOS 2.31 present.
Handle 0x0002, DMI type 2, 8 bytes
Base Board Information
Manufacturer: Intel Corporation
Product Name: 440BX Desktop Reference Platform
Version: None
Serial Number: None
Handle 0x001A, DMI type 10, 8 bytes
On Board Device 1 Information
Type: Video
Status: Disabled
Description: VMware SVGA II
On Board Device 2 Information
Type: Sound
Status: Disabled
Description: ES1371
#4) Getting HW information about chassis
Use -t chassis for fetch details about system chassis
# dmidecode -t chassis
# dmidecode 2.9
SMBIOS 2.31 present.
Handle 0x0003, DMI type 3, 17 bytes
Chassis Information
Manufacturer: No Enclosure
Type: Other
Lock: Not Present
Version: N/A
Serial Number: None
Asset Tag: No Asset Tag
Boot-up State: Safe
Power Supply State: Safe
Thermal State: Safe
Security Status: None
OEM Information: 0x00001234Similarly, you find the hardware information like processor, memory, cache, connector and slot.
# dmidecode -t memory
# dmidecode -t cashe
# dmidecode -t processor
# dmidecode -t connector
# dmidecode -t slotThere is DMI types; this DMI type id will give information about a particular hardware component of your system. There are more than 100 types, for examples here are some type ids.
DMI TYPES
The SMBIOS specification defines the following DMI type information:
Type DMI
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 SupplyAdditionally, type 126 is used for disabled entries and type 127 is an end-of-table marker. Types 128 to 255 are for OEM-specific data. Dmidecode will display these entries by default, but it can only decode them when the vendors have contributed documentation or code for them.
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
5) Get processor hardware information
Using type id we can get processor information
# dmidecode -t 4 | head
# dmidecode 2.9
SMBIOS 2.31 present.
Handle 0x0004, DMI type 4, 35 bytes
Processor Information
Socket Designation: CPU socket #0
Type: Central Processor
Family: Unknown
Manufacturer: AuthenticAMD
ID: 23 0F 10 00 FF FB 8B 076) Get 64-bit Memory Error
Use -t id to get memory error information
# dmidecode -t 33
# dmidecode 2.9
SMBIOS 2.31 present.
Handle 0x002A, DMI type 33, 31 bytes
64-bit Memory Error Information
Type: OK
Granularity: Unknown
Operation: Unknown
Vendor Syndrome: Unknown
Memory Array Address: 0x0000000080000000
Device Address: 0x0000000080000000
Resolution: Unknown7) Grep option to get product details
Since its big file, you can use grep command to search for a string you look for.
# dmidecode | grep -i prodConclusion
This tutorial we learned how to use dmidecode command and its options to get different hardware information. I hope you enjoyed reading and please leave your suggestions.
