在日常运维工作中，经常需要查看系统的硬件信息，linux信息查看并不像windows那么直观
这里我罗列了查看系统信息的实用命令，并做了分类，实例解说。
查看系统版本
[email protected]:~$cat /etc/issue
CentOS release 6.8 (Final)
Kernel \r on an \m
[email protected]:~$cat /etc/redhat-release
CentOS release 6.8 (Final)
查看系统时32位还是64位
[email protected]:~$ getconf LONG_BIT
64
内核查看
[email protected]:~$uname -a
cpu
lscpu命令，查看的是cpu的统计信息.
[email protected]:~$ lscpu
Architecture: i686 #cpu架构
CPU op-mode(s): 32-bit, 64-bit
Byte Order: Little Endian #小尾序
CPU(s): 4 #总共有4核
On-line CPU(s) list: 0-3
Thread(s) per core: 1 #每个cpu核，只能支持一个线程，即不支持超线程
Core(s) per socket: 4 #每个cpu，有4个核
Socket(s): 1 #总共有1一个cpu
Vendor ID: GenuineIntel #cpu产商 intel
CPU family: 6
Model: 42
Stepping: 7
CPU MHz: 1600.000
BogoMIPS: 5986.12
Virtualization: VT-x #支持cpu虚拟化技术
L1d cache: 32K
L1i cache: 32K
L2 cache: 256K
L3 cache: 6144K
查看/proc/cpuinfo,可以知道每个cpu信息，如每个CPU的型号，主频等。
也可以top命令进去后，按数字“1”，即可查看cpu是多少核
#cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 42
model name : Intel(R) Core(TM) i5-2320 CPU @ 3.00GHz
.....
上面输出的是第一个cpu部分信息，还有3个cpu信息省略了。
内存
概要查看内存情况
free -m
total used free shared buffers cached
Mem: 3926 3651 274 0 12 404
-/+ buffers/cache: 3235 691
Swap: 9536 31 9505
这里的单位是MB，总共的内存是3926MB。
查看内存详细使用
# cat /proc/meminfo
MemTotal: 4020868 kB
MemFree: 230884 kB
Buffers: 7600 kB
Cached: 454772 kB
SwapCached: 836 kB
.....
复制代码
查看内存硬件信息
复制代码
dmidecode -t memory
# dmidecode 2.11
SMBIOS 2.7 present.
Handle 0x0008, DMI type 16, 23 bytes
Physical Memory Array
Location: System Board Or Motherboard
....
Maximum Capacity: 32 GB
....
Handle 0x000A, DMI type 17, 34 bytes
....
Memory Device
Array Handle: 0x0008
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 4096 MB
.....
复制代码
我的主板有4个槽位，只用了一个槽位，上面插了一条4096MB的内存。
磁盘
查看硬盘和分区分布
复制代码
# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 465.8G 0 disk
├─sda1 8:1 0 1G 0 part /boot
├─sda2 8:2 0 9.3G 0 part [SWAP]
├─sda3 8:3 0 74.5G 0 part /
├─sda4 8:4 0 1K 0 part
├─sda5 8:5 0 111.8G 0 part /home
└─sda6 8:6 0 269.2G 0 part
复制代码
显示很直观
如果要看硬盘和分区的详细信息
复制代码
# fdisk -l
Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00023728
Device Boot Start End Blocks Id System
/dev/sda1 * 2048 2148351 1073152 83 Linux
/dev/sda2 2148352 21680127 9765888 82 Linux swap / Solaris
/dev/sda3 21680128 177930239 78125056 83 Linux
/dev/sda4 177932286 976771071 399419393 5 Extended/dev/sda5 177932288 412305407 117186560 83 Linux
/dev/sda6 412307456 976771071 282231808 83 Linux
复制代码
网卡
查看网卡硬件信息
# lspci | grep -i ‘eth‘
02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 06)
查看系统的所有网络接口
# ifconfig -a
eth0 Link encap:以太网 硬件地址 b8:97:5a:17:b3:8f
.....
lo Link encap:本地环回
.....
或者是
ip link show
1: lo: <LOOPBACK> mtu 16436 qdisc noqueue state DOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether b8:97:5a:17:b3:8f brd ff:ff:ff:ff:ff:ff
如果要查看某个网络接口的详细信息，例如eth0的详细参数和指标
复制代码
# ethtool eth0
Settings for eth0:
Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Half 1000baseT/Full #支持千兆半双工，全双工模式
Supported pause frame use: No
Supports auto-negotiation: Yes #支持自适应模式，一般都支持
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Half 1000baseT/Full
Advertised pause frame use: Symmetric Receive-only
Advertised auto-negotiation: Yes #默认使用自适应模式
Link partner advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
.....
Speed: 100Mb/s #现在网卡的速度是100Mb,网卡使用自适应模式，所以推测路由是100Mb，导致网卡从支持千兆，变成要支持百兆
Duplex: Full #全双工
.....
Link detected: yes #表示有网线连接，和路由是通的
复制代码
其他
查看pci信息，即主板所有硬件槽信息。
复制代码
lspci
00:00.0 Host bridge: Intel Corporation 2nd Generation Core Processor Family DRAM Controller (rev 09) #主板芯片
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) #显卡
00:14.0 USB controller: Intel Corporation Panther Point USB xHCI Host Controller (rev 04) #usb控制器
00:16.0 Communication controller: Intel Corporation Panther Point MEI Controller #1 (rev 04)
00:1a.0 USB controller: Intel Corporation Panther Point USB Enhanced Host Controller #2 (rev 04)
00:1b.0 Audio device: Intel Corporation Panther Point High Definition Audio Controller (rev 04) #声卡
00:1c.0 PCI bridge: Intel Corporation Panther Point PCI Express Root Port 1 (rev c4) #pci 插槽
00:1c.2 PCI bridge: Intel Corporation Panther Point PCI Express Root Port 3 (rev c4)
00:1c.3 PCI bridge: Intel Corporation Panther Point PCI Express Root Port 4 (rev c4)
00:1d.0 USB controller: Intel Corporation Panther Point USB Enhanced Host Controller #1 (rev 04)
00:1f.0 ISA bridge: Intel Corporation Panther Point LPC Controller (rev 04)
00:1f.2 IDE interface: Intel Corporation Panther Point 4 port SATA Controller [IDE mode] (rev 04) #硬盘接口
00:1f.3 SMBus: Intel Corporation Panther Point SMBus Controller (rev 04)
00:1f.5 IDE interface: Intel Corporation Panther Point 2 port SATA Controller [IDE mode] (rev 04) #硬盘接口
02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 06) #网卡
03:00.0 PCI bridge: Integrated Technology Express, Inc. Device 8893 (rev 41)
复制代码
如果要更详细的信息:lspci -v 或者 lspci -vv
如果要看设备树:lscpi -t
查看bios信息
复制代码
# dmidecode -t bios
......
BIOS Information
Vendor: American Megatrends Inc.
Version: 4.6.5
Release Date: 04/25/2012
.......
BIOS Revision: 4.6
......
复制代码
dmidecode以一种可读的方式dump出机器的DMI(Desktop Management Interface)信息。这些信息包括了硬件以及BIOS，既可以得到当前的配置，也可以得到系统支持的最大配置，比如说支持的最大内存数等。
如果要查看所有有用信息
dmidecode -q
里面包含了很多硬件信息。