Essential Linux Commands to Inspect Hardware and System Resources

lshw

The lshw utility provides a comprehensive list of hardware components on the host. It extracts data from /proc and can display a full report or a concise summary with the -short option.

[alvin@VM_0_16_centos ~]$ sudo lshw -short
# (output truncated for brevity)
H/W path        Device   Class        Description
==========================================================
system          Bochs
/0              bus      Motherboard
/0/0            memory   96KiB BIOS
/0/401          processor Intel(R) Xeon(R) CPU E5-26xx v4
/0/1000         memory   2GiB System Memory
/0/1000/0      memory   2GiB DIMM RAM
/0/100/0       bridge   440FX - 82441FX PMC [Natoma]
/0/100/1       bridge   82371SB PIIX3 ISA [Natoma/Triton II]
/0/100/1.1/0.1 /dev/cdrom  disk QEMU DVD-ROM
/0/100/1.2     bus      UHCI Host Controller
/0/100/4       generic  Virtio memory balloon
/0/1           system   PnP device PNP0b0
/0/2           input    PnP device PNP0303

lscpu

The lscpu command prints CPU architecture information without requiring any options.

[alvin@VM_0_16_centos ~]$ lscpu
Architecture:        x86_64
CPU op-mode(s):      32-bit, 64-bit
Byte Order:          Little Endian
CPU(s):              1
On-line CPU(s) list: 0
Thread(s) per core:  1
Core(s) per socket:  1
Socket(s):           1
NUMA node(s):        1
Vendor ID:           GenuineIntel
CPU family:          6
Model:               79
Model name:          Intel(R) Xeon(R) CPU E5-26xx v4
Stepping:            1
CPU MHz:             2399.988
BogoMIPS:            4799.97
Hypervisor vendor:   KVM
Virtualization type: full
L1d cache:           32K
L1i cache:           32K
L2 cache:            4096K
NUMA node0 CPU(s):   0

lsusb

lsusb

lists all USB devices attached to the system. Use the -v flag for verbose details.

[alvin@VM_0_16_centos ~]$ lsusb
Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp. SMSC9512/9514 Fast Ethernet Adapter
Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp. SMC9514 Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

lsscsi

lsscsi

displays information about SCSI and SATA devices such as hard drives and optical drives.

[alvin@VM_0_16_centos ~]$ lsscsi
[0:0:1:0]    cd/dvd  QEMU     QEMU DVD-ROM     1.2.  /dev/sr0

lspci

The lspci command enumerates all PCI buses and devices, providing details for VGA adapters, network cards, USB controllers, and more.

[alvin@VM_0_16_centos ~]$ lspci
00:00.0 Host bridge: Intel Corporation 440FX - 82441FX PMC [Natoma] (rev 02)
00:01.0 ISA bridge: Intel Corporation 82371SB PIIX3 ISA [Natoma/Triton II]
00:01.1 IDE interface: Intel Corporation 82371SB PIIX3 IDE [Natoma/Triton II]
00:01.2 USB controller: Intel Corporation 82371SB PIIX3 USB [Natoma/Triton II] (rev 01)
00:01.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 03)
00:02.0 VGA compatible controller: Cirrus Logic GD 5446
00:03.0 Ethernet controller: Red Hat, Inc Virtio network device
00:04.0 SCSI storage controller: Red Hat, Inc Virtio block device
00:05.0 Unclassified device [00ff]: Red Hat, Inc Virtio memory balloon

df

The df command reports filesystem disk space usage. Adding the -h flag formats sizes in human‑readable units (K, M, G).

[alvin@VM_0_16_centos ~]$ df -h
Filesystem      Size  Used Avail Use% Mounted on
/dev/vda1        50G  7.5G   40G  16% /
devtmpfs        911M     0  911M   0% /dev
tmpfs           920M   68K  920M   1% /dev/shm
tmpfs           920M  364K  920M   1% /run
tmpfs           184M     0  184M   0% /run/user/0
tmpfs           184M     0  184M   0% /run/user/1001
tmpfs           184M     0  184M   0% /run/user/1000

free

The free command shows total, used, and free memory. The -m option displays values in megabytes.

[alvin@VM_0_16_centos ~]$ free -m
              total   used   free   shared  buff/cache  available
Mem:          1839    221    156       0        1461        1400
Swap:            0      0      0