Introduction
A key skill that you need to have as a Linux System Administrator is knowing how to view information about the currently installed Hardware in your system.
And in this lesson, we’re going to look at various tools that you can use to do this.
1. Exploring /proc File System
Now believe it or not one of the best tools for looking at hardware information is the good old /proc directory.
Now we’ve talked about /proc before.
Remember the /proc directory doesn’t really exist in the file system, instead it’s a pseudo file system that dynamically created whenever you access it.
Now as you can see here the /proc directory contains a whole bunch of subdirectories and each one of these subdirectories that you see here in blue represents a process that’s currently running on your system.
If you want to view information about a particular process you could go into the appropriate directory here and there, you’ll find information about that running process.
# ls /proc/
985 driver loadavg slabinfo 1 11 1345 154 1646 17508 1831 2 2174 2336 2428 2492 2675 464 617
986 execdomains locks softirqs 10 1100 1355 155 165 1751 1839 20 2182 2337 2430 25 2681 465 648
987 fb mdstat stat 1004 1160 1360 156 16599 1753 1849 2000 2195 2341 2432 2525 27 470 8
990 filesystems meminfo swaps 1006 1161 1365 157 166 17550 19 2004 22 2344 2440 2532 2741 483 836
991 fs misc sys 1009 1169 1371 158 167 17551 1930 2008 2201 2349 2442 2549 2748 484 9
acpi interrupts modules sysrq-trigger 1014 1184 1423 1585 168 17569 1934 2013 2205 2352 2450 2551 28 509 920
asound iomem mounts sysvipc 1015 1188 146 1586 169 176 1937 2019 2210 2363 2452 2570 29 510 921
buddyinfo ioports mpt thread-self 1018 1191 1466 159 17 17609 1941 2021 2216 2368 2453 2572 3 511 946
bus irq mtrr timer_list 1019 1197 147 16 170 177 1949 2031 2225 2371 2456 2598 30 512 948
cgroups kallsyms net tty 1022 12 148 160 17039 178 1953 2040 2275 2385 2457 26 4 513 950
cmdline kcore pagetypeinfo uptime 1038 12766 149 161 171 179 1974 2044 2295 2389 2469 2602 450 514 962
consoles keys partitions version 1043 12785 15 1612 172 18 1981 2048 23 2393 2470 2605 451 515 963
cpuinfo key-users pressure vmallocinfo 1046 12938 150 162 17285 180 1985 2051 2303 2397 2474 2606 454 516 978
crypto kmsg sched_debug vmstat 1048 12939 151 1626 173 181 1989 2073 2320 24 2475 2609 455 517 979
devices kpagecgroup schedstat zoneinfo 1068 12951 1518 16291 17341 182 1991 2092 2323 2409 2476 2613 457 53 982
diskstats kpagecount scsi 1070 12952 152 163 174 1827 1992 21 2328 2410 2482 2625 462 6 983
dma kpageflags self 1077 13 153 164 175 183 1996 2166 2331 2426 2489 2653 463 6131 984But that’s not what we’re concerned about in this lesson.
What we are concerned about are the other files over here within this directory these files contain information about the hardware in your system.
1.1 /proc/cpuinfo explained
For example, the /proc/cpuinfo file contains details about the CPU that’s installed in the system.
And because this is just a text file you can use the cat, less, more or any other text editor you want to view the contents of this file.
Suggested Read: cat Command Examples in Linux
In this example, I use the cat command to view the cpuinfo file on this particular system and when we do I learn that I have an Intel(R) Core(TM) i5-6300U CPU @ 2.40GHz and right here it tells me that it’s a 1 core processor.
I can also see how much cache memory is available on this cpu, there’s more information displayed in the cpuinfo file that we can show on the screen at one time.
# cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 78
model name : Intel(R) Core(TM) i5-6300U CPU @ 2.40GHz
stepping : 3
microcode : 0xcc
cpu MHz : 2495.999
cache size : 3072 KB
physical id : 0
siblings : 1
core id : 0
cpu cores : 1
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 22
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx pdpe1gb rdtscp lm constant_tsc arch_perfmon nopl xtopology tsc_reliable nonstop_tsc cpuid pni pclmulqdq ssse3 fma cx16 pcid sse4_1 sse4_2 x2apic movbe popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm abm 3dnowprefetch cpuid_fault invpcid_single pti ssbd ibrs ibpb stibp fsgsbase tsc_adjust bmi1 avx2 smep bmi2 invpcid rdseed adx smap clflushopt xsaveopt xsavec xgetbv1 xsaves arat md_clear flush_l1d arch_capabilities
bugs : cpu_meltdown spectre_v1 spectre_v2 spec_store_bypass l1tf mds swapgs itlb_multihit
bogomips : 4991.99
clflush size : 64
cache_alignment : 64
address sizes : 45 bits physical, 48 bits virtual
power management:1.2 /proc/devices
In addition, there’s another file in here called /proc/devices.
The devices file contains a list of all the hardware devices installed in the system.
# cat /proc/devices
Character devices:
1 mem
4 /dev/vc/0
4 tty
4 ttyS
5 /dev/tty
5 /dev/console
5 /dev/ptmx
7 vcs
10 misc
13 input
14 sound
21 sg
29 fb
116 alsa
128 ptm
136 pts
162 raw
180 usb
188 ttyUSB
189 usb_device
202 cpu/msr
203 cpu/cpuid
216 rfcomm
226 drm
243 aux
244 hidraw
245 usbmon
246 bsg
247 watchdog
248 ptp
249 pps
250 cec
251 rtc
252 dax
253 tpm
254 gpiochip
Block devices:
8 sd
9 md
11 sr
65 sd
66 sd
67 sd
68 sd
69 sd
70 sd
71 sd
128 sd
129 sd
130 sd
131 sd
132 sd
133 sd
134 sd
135 sd
253 device-mapper
254 mdp
259 blkext1.3 /proc/dma
There’s another file here called /proc/dma, this contains a list of all the dma channel assignments in the system.
# cat /proc/dma
4: cascade1.4 /proc/interrupts
Another interesting file is the /proc/interrupts file, the contents of a sample interrupts file is shown here.
As you can see it contains a list of IRQ assignments in the system.
For example, we can see that our two ATA controllers on the system are assigned to interrupts 14 and 15, Our Network port is assigned to use interrupt 19, Our USB ports are assigned to use interrupt 17 and 18.
# cat interrupts
CPU0
0: 90 IO-APIC 2-edge timer
1: 13352 IO-APIC 1-edge i8042
8: 1 IO-APIC 8-edge rtc0
9: 0 IO-APIC 9-fasteoi acpi
12: 191742 IO-APIC 12-edge i8042
14: 0 IO-APIC 14-edge ata_piix
15: 56679 IO-APIC 15-edge ata_piix
16: 79971 IO-APIC 16-fasteoi vmwgfx, snd_ens1371
17: 375078 IO-APIC 17-fasteoi ehci_hcd:usb1, ioc0
18: 976 IO-APIC 18-fasteoi uhci_hcd:usb2
19: 223499 IO-APIC 19-fasteoi ens33
24: 0 PCI-MSI 344064-edge PCIe PME, pciehp
25: 0 PCI-MSI 346112-edge PCIe PME, pciehp
26: 0 PCI-MSI 348160-edge PCIe PME, pciehp
27: 0 PCI-MSI 350208-edge PCIe PME, pciehp
28: 0 PCI-MSI 352256-edge PCIe PME, pciehp
29: 0 PCI-MSI 354304-edge PCIe PME, pciehp
30: 0 PCI-MSI 356352-edge PCIe PME, pciehp
31: 0 PCI-MSI 358400-edge PCIe PME, pciehp
32: 0 PCI-MSI 360448-edge PCIe PME, pciehp
33: 0 PCI-MSI 362496-edge PCIe PME, pciehp
34: 0 PCI-MSI 364544-edge PCIe PME, pciehp
35: 0 PCI-MSI 366592-edge PCIe PME, pciehp
36: 0 PCI-MSI 368640-edge PCIe PME, pciehp
37: 0 PCI-MSI 370688-edge PCIe PME, pciehp
38: 0 PCI-MSI 372736-edge PCIe PME, pciehp
39: 0 PCI-MSI 374784-edge PCIe PME, pciehp
40: 0 PCI-MSI 376832-edge PCIe PME, pciehp
41: 0 PCI-MSI 378880-edge PCIe PME, pciehp
42: 0 PCI-MSI 380928-edge PCIe PME, pciehp
43: 0 PCI-MSI 382976-edge PCIe PME, pciehp
44: 0 PCI-MSI 385024-edge PCIe PME, pciehp
45: 0 PCI-MSI 387072-edge PCIe PME, pciehp
46: 0 PCI-MSI 389120-edge PCIe PME, pciehp
47: 0 PCI-MSI 391168-edge PCIe PME, pciehp
48: 0 PCI-MSI 393216-edge PCIe PME, pciehp
49: 0 PCI-MSI 395264-edge PCIe PME, pciehp
50: 0 PCI-MSI 397312-edge PCIe PME, pciehp
51: 0 PCI-MSI 399360-edge PCIe PME, pciehp
52: 0 PCI-MSI 401408-edge PCIe PME, pciehp
53: 0 PCI-MSI 403456-edge PCIe PME, pciehp
54: 0 PCI-MSI 405504-edge PCIe PME, pciehp
55: 0 PCI-MSI 407552-edge PCIe PME, pciehp
56: 7782 PCI-MSI 129024-edge vmw_vmci
57: 0 PCI-MSI 129025-edge vmw_vmci
NMI: 0 Non-maskable interrupts
LOC: 3863622 Local timer interrupts
SPU: 0 Spurious interrupts
PMI: 0 Performance monitoring interrupts
IWI: 0 IRQ work interrupts
RTR: 0 APIC ICR read retries
RES: 0 Rescheduling interrupts
CAL: 0 Function call interrupts
TLB: 0 TLB shootdowns
TRM: 0 Thermal event interrupts
THR: 0 Threshold APIC interrupts
DFR: 0 Deferred Error APIC interrupts
MCE: 0 Machine check exceptions
MCP: 177 Machine check polls
HYP: 0 Hypervisor callback interrupts
HRE: 0 Hyper-V reenlightenment interrupts
HVS: 0 Hyper-V stimer0 interrupts
ERR: 0
MIS: 0
PIN: 0 Posted-interrupt notification event
NPI: 0 Nested posted-interrupt event
PIW: 0 Posted-interrupt wakeup event1.5 /proc/iomem
There’s also a file here called /proc/iomem which contains a list of I/O port assignments on the system.
# cat /proc/iomem
00000000-00000fff : Reserved
00001000-0009ebff : System RAM
0009ec00-0009ffff : Reserved
000a0000-000bffff : PCI Bus 0000:00
000c0000-000c7fff : Video ROM
000ca000-000cafff : Adapter ROM
000cc000-000cffff : PCI Bus 0000:00
000d0000-000d3fff : PCI Bus 0000:00
000d4000-000d7fff : PCI Bus 0000:00
000d8000-000dbfff : PCI Bus 0000:00
000dc000-000fffff : Reserved
000f0000-000fffff : System ROM
00100000-3fedffff : System RAM
1aa00000-1b6013f0 : Kernel code
1b6013f1-1be19eff : Kernel data
1c5ad000-1cbfffff : Kernel bss
2a000000-33ffffff : Crash kernel
3fee0000-3fefefff : ACPI Tables
3feff000-3fefffff : ACPI Non-volatile Storage
3ff00000-3fffffff : System RAM1.6 /proc/modules
Another very useful file is the /proc/modules file, this file contains a list of all the kernel modules currently being used by the system.
An example of a /proc/modules file is shown here.
I’ve just used the cat command to view it and here you can see all the various kernel modules that have been loaded such as our bluetooth driver which is used to provide support for Bluetooth devices in the system.
# cat /proc/modules
uinput 20480 1 - Live 0xffffffffc0adb000
fuse 131072 3 - Live 0xffffffffc0a3d000
rfcomm 86016 6 - Live 0xffffffffc0871000
xt_CHECKSUM 16384 1 - Live 0xffffffffc0a34000
ipt_MASQUERADE 16384 1 - Live 0xffffffffc0a2f000
xt_conntrack 16384 1 - Live 0xffffffffc0a2a000
ipt_REJECT 16384 1 - Live 0xffffffffc0a23000
nft_counter 16384 16 - Live 0xffffffffc0a1e000
nf_nat_tftp 16384 0 - Live 0xffffffffc0a19000
nft_objref 16384 1 - Live 0xffffffffc0a14000
nf_conntrack_tftp 16384 3 nf_nat_tftp, Live 0xffffffffc0a0f000
tun 53248 1 - Live 0xffffffffc0a01000
bridge 192512 0 - Live 0xffffffffc09cf000
stp 16384 1 bridge, Live 0xffffffffc09ca000
llc 16384 2 bridge,stp, Live 0xffffffffc09c5000
bluetooth 634880 27 rfcomm,bnep,btusb,btrtl,btbcm,btintel, Live 0xffffffffc05a9000
ecdh_generic 24576 1 bluetooth, Live 0xffffffffc051f000
rfkill 28672 5 bluetooth, Live 0xffffffffc02ba0001.7 /proc/scsi/ Directory explained
There is a subfolder here named scsi.
The scsi directory contains additional files that contain information about the various scsi devices on your system.
# ls /proc/scsi/
device_info mptspi scsi sg
# cat /proc/scsi/scsi
Attached devices:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
Vendor: VMware, Model: VMware Virtual S Rev: 1.0
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi0 Channel: 00 Id: 01 Lun: 00
Vendor: VMware, Model: VMware Virtual S Rev: 1.0
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi0 Channel: 00 Id: 02 Lun: 00
Vendor: VMware, Model: VMware Virtual S Rev: 1.0
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi0 Channel: 00 Id: 03 Lun: 00
Vendor: VMware, Model: VMware Virtual S Rev: 1.0
Type: Direct-Access ANSI SCSI revision: 02
Host: scsi2 Channel: 00 Id: 00 Lun: 00
Vendor: NECVMWar Model: VMware IDE CDR10 Rev: 1.00
Type: CD-ROM ANSI SCSI revision: 051.8 /proc/bus/ Directory explained
There’s also a folder over here called bus, within bus is a file named devices which contains information about the various USB devices on the system.
# ls /proc/bus/
input pci
# ls /proc/bus/input/
devices handlers# cat devices
I: Bus=0019 Vendor=0000 Product=0001 Version=0000
N: Name="Power Button"
P: Phys=LNXPWRBN/button/input0
S: Sysfs=/devices/LNXSYSTM:00/LNXPWRBN:00/input/input0
U: Uniq=
H: Handlers=kbd event0
B: PROP=0
B: EV=3
B: KEY=10000000000000 0
I: Bus=0011 Vendor=0001 Product=0001 Version=ab41
N: Name="AT Translated Set 2 keyboard"
P: Phys=isa0060/serio0/input0
S: Sysfs=/devices/platform/i8042/serio0/input/input1
U: Uniq=
H: Handlers=sysrq kbd leds event1
B: PROP=0
B: EV=120013
B: KEY=402000000 3803078f800d001 feffffdfffefffff fffffffffffffffe
B: MSC=10
B: LED=7
I: Bus=0011 Vendor=0002 Product=0013 Version=0006
N: Name="VirtualPS/2 VMware VMMouse"
P: Phys=isa0060/serio1/input1
S: Sysfs=/devices/platform/i8042/serio1/input/input4
U: Uniq=
H: Handlers=mouse0 event2
B: PROP=0
B: EV=b
B: KEY=70000 0 0 0 0
B: ABS=31.9 /proc/diskstats
The /proc/diskstats file displays the I/O statistics of block devices. Each line contains the following 14 fields:
- Major number
- Minor number
- Device name
- Reads completed successfully
- Reads merged
- Sectors read
- Time spent reading (ms)
- Writes completed
- Writes merged
- Sectors written
- time spent writing (ms)
- I/Os currently in progress
- Time spent doing I/Os (ms)
- Weighted time spent doing I/Os (ms)
An example of a /proc/diskstats file is shown here.
# cat /proc/diskstats
8 0 sda 364602 84167 34602359 214193 42116 376022 4221929 47325 0 190620 134354 0 0 0 0
8 1 sda1 599 0 100694 288 17 4 96 6 0 503 105 0 0 0 0
8 2 sda2 142790 83948 1850352 77867 21907 373586 3163944 32211 0 79272 61332 0 0 0 0
8 3 sda3 221046 219 32616689 135978 20192 2432 1057889 15107 0 130180 72903 0 0 0 0
8 16 sdb 7248 0 486546 961 698 830 350550 307 0 3220 164 0 0 0 0
8 17 sdb1 435 0 28880 80 127 83 50841 57 0 347 30 0 0 0 0
8 18 sdb2 414 0 29288 34 23 0 1915 4 0 168 3 0 0 0 0
8 19 sdb3 454 0 28576 40 126 83 50833 55 0 260 22 0 0 0 0
8 32 sdc 2201 0 163248 265 131 0 11523 53 0 1213 41 0 0 0 0
8 48 sdd 1609 0 137440 212 129 0 11507 57 0 1086 36 0 0 0 0
11 0 sr0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
253 0 dm-0 310 0 9616 51 189 0 49302 139 0 169 190 0 0 0 0
253 1 dm-1 262 0 7528 29 189 0 49302 88 0 127 117 0 0 0 0Source: kernel.org
1.10 /proc/swaps
/proc/swaps measures swap space and its utilization.
This file provides a snapshot of every swap file name, the type of swap space, the total size, and the amount of space in use (in kilobytes).
# cat /proc/swaps
Filename Type Size Used Priority
/dev/sda2 partition 2097148 718592 -2Suggested Read: How to create swap partition in Linux
1.11 /proc/filesystems
/proc/filesystems file displays a list of the file system types currently supported by the kernel.
# cat /proc/filesystems
nodev sysfs
nodev rootfs
nodev ramfs
nodev bdev
nodev proc
nodev cpuset
nodev cgroup
nodev cgroup2
nodev tmpfs
nodev devtmpfs
nodev configfs
nodev debugfs
nodev tracefs
nodev securityfs
nodev sockfs
nodev bpf
nodev pipefs
nodev hugetlbfs
nodev devpts
nodev autofs
nodev pstore
nodev mqueue
nodev selinuxfs
xfs
ext3
ext2
ext4
nodev rpc_pipefs
fuseblk
nodev fuse
nodev fusectl1.12 /proc/partitions
/proc/partitions: This file contains partition block allocation information.
# cat /proc/partitions
major minor #blocks name
8 0 20971520 sda
8 1 307200 sda1
8 2 2097152 sda2
8 3 18566144 sda3
8 16 3145728 sdb
8 17 512000 sdb1
8 18 512000 sdb2
8 19 512000 sdb3
8 32 3145728 sdc
8 48 3145728 sdd
11 0 1048575 sr0
253 0 512000 dm-0
253 1 512000 dm-1Suggested Read:
- fdisk Command: How to Create Disk Partitions (MBR) in Linux
- gdisk Command: How to Create GUID Partitions (GPT) in Linux
1.13 /proc/meminfo
This is one of the more commonly used files in the /proc directory, as it reports a large amount of valuable information about the system’s RAM usage.
# cat meminfo
MemTotal: 810492 kB
MemFree: 85700 kB
MemAvailable: 141600 kB
Buffers: 64 kB
Cached: 148356 kB
SwapCached: 59496 kB
Active: 214320 kB
Inactive: 178792 kB
Active(anon): 130152 kB
Inactive(anon): 125584 kB
Active(file): 84168 kB
Inactive(file): 53208 kB
Unevictable: 0 kB
Mlocked: 0 kB
SwapTotal: 2097148 kB
SwapFree: 1371388 kB
Dirty: 32 kB
Writeback: 0 kB
AnonPages: 237956 kB
Mapped: 64296 kB
Shmem: 11044 kB
KReclaimable: 55044 kB
Slab: 166788 kB
SReclaimable: 55044 kB
SUnreclaim: 111744 kB
KernelStack: 11436 kB
PageTables: 49720 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 2502392 kB
Committed_AS: 4800280 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 0 kB
VmallocChunk: 0 kB
Percpu: 57856 kB
HardwareCorrupted: 0 kB
AnonHugePages: 81920 kB
ShmemHugePages: 0 kB
ShmemPmdMapped: 0 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
Hugetlb: 0 kB
DirectMap4k: 286592 kB
DirectMap2M: 761856 kB
DirectMap1G: 0 kB1.14 /proc/uptime
This file contains information detailing how long the system has been on since its last restart.
# cat /proc/uptime
69274.12 67735.131.15 /proc/version
This file specifies the version of the Linux kernel, the version of gcc used to compile the kernel, and the time of kernel compilation. It also contains the kernel compiler’s user name.
# cat /proc/version
Linux version 4.18.0-193.el8.x86_64 ([email protected]) (gcc version 8.3.1 20191121 (Red Hat 8.3.1-5) (GCC)) #1 SMP Fri May 8 10:59:10 UTC 2020You can also get the same information using the uname command.
# uname -a
Linux localhost.localdomain 4.18.0-193.el8.x86_64 #1 SMP Fri May 8 10:59:10 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux2. Exploring /sys File System
Now in addition to the /proc directory there’s another directory within your Linux file system named /sys and it also provides information about the hardware installed in the system.
Now the file system within /sys actually organized into a kind of tree structure that’s grouped by the hardware bus, the hardware devices and their associated drivers.
The top level of the /sys directory is shown here, and it contains many subdirectories to organize this information.
# ls /sys/
block bus class dev devices firmware fs hypervisor kernel module powerFor example, the block directory contains a symbolic link file for each block device in the system.
2.1 /sys/bus/ Directory explained
The bus directory contains a directory for each data bus in the system such as your PCI bus, your scsi bus and your USB bus.
And then within each bus directory there are two subdirectories called devices and drivers.
# cd /sys/bus/
# ls
ac97 clockevents cpu event_source i2c memory nvmem platform serio thunderbolt usb-serial xen
acpi clocksource dax gpio machinecheck mipi-dsi pci pnp snd_seq typec virtio
cec container edac hid mdio_bus node pci_express scsi spi usb workqueue
# ls cpu/
devices drivers drivers_autoprobe drivers_probe uevent
# ls memory/
devices drivers drivers_autoprobe drivers_probe uevent
These are shown right here. I’m inside the USB bus directory.
# cd usb/
# ls
devices drivers drivers_autoprobe drivers_probe ueventThe devices subdirectory contains entries for every device connected to that bus while the drivers directory contains subdirectories for each driver that’s loaded for a given device on that bus.
2.2 Explaining /sys/class/, /sys/devices/, /sys/module/ Directories
Now within the /sys directory itself is a directory called class.
# ls /sys/
block bus class dev devices firmware fs hypervisor kernel module powerThe /sys/class directory contains a listing of all device classes available.
The /sys/devices directory contains an entry for every hardware device that’s been discovered on the system.
There’s also directory here called /sys/module.
Now the /sys/module directory contains many subdirectories one for each module currently loaded into the kernel.
For example, here’s our sub directory for the Bluetooth kernel module, Mouse driver, subdirectory for our Keyboard driver and so on.
# cd /sys/module/
8250 debug_core intel_rapl_common nf_conntrack nft_reject slab_common tpm_tis_core
ac97_bus dm_mod intel_rapl_msr nf_conntrack_ipv4 nft_reject_inet snd ttm
acpi drm intel_rapl_perf nf_conntrack_ipv6 page_alloc snd_ac97_codec tun
acpiphp drm_kms_helper ip6_tables nf_conntrack_tftp pcie_aspm snd_ens1371 uhci_hcd
ata_generic dynamic_debug ip_set nf_defrag_ipv4 pciehp snd_pcm uinput
ata_piix e1000 ip_tables nf_defrag_ipv6 pci_hotplug snd_rawmidi usbcore
battery ecdh_generic ipt_MASQUERADE nf_nat pcmcia_core snd_seq usbhid
blk_cgroup edac_core ipt_REJECT nf_nat_ipv4 pcspkr snd_seq_device uv_nmi
block efi_pstore ipv6 nf_nat_ipv6 printk snd_seq_midi virtio_pci
bluetooth efivars jbd2 nf_nat_tftp processor snd_seq_midi_event vmd
bnep ehci_hcd joydev nfnetlink psmouse snd_timer vmw_balloon
bridge ext4 kdb nf_reject_ipv4 pstore soundcore vmwgfx
btbcm fb kernel nf_reject_ipv6 random spurious vmw_vmci
btintel fb_sys_fops keyboard nf_tables rcupdate srcutree vmw_vsock_vmci_transport
btrtl firmware_class kgdboc nf_tables_set rcutree sr_mod vsock
btusb fuse kgdbts nft_chain_nat_ipv4 rfcomm stp vt
button ghash_clmulni_intel libata nft_chain_nat_ipv6 rfkill sunrpc watchdog
cdrom haltpoll libcrc32c nft_chain_route_ipv4 rng_core suspend workqueue
cec hid llc nft_chain_route_ipv6 rtc_cmos syscopyarea xfs
configfs hid_magicmouse mbcache nft_compat scsi_dh_alua sysfillrect xhci_hcd
cpufreq hid_ntrig md_mod nft_counter scsi_dh_rdac sysimgblt xt_CHECKSUM
cpuidle i2c_piix4 module nft_ct scsi_mod sysrq xt_conntrack
crc32c_intel i8042 mousedev nft_fib scsi_transport_spi tcp_cubic xz_dec
crc32_pclmul ima mptbase nft_fib_inet sd_mod thermal zswap
crc_t10dif intel_idle mptscsih nft_fib_ipv4 serio_raw tpm
crct10dif_pclmul intel_pmc_core mptspi nft_fib_ipv6 sg tpm_crb
cryptomgr intel_pmc_core_pltdrv netpoll nft_objref shpchp tpm_tis
3. Commands to Check Hardware Information on Linux
Now in addition to the /proc and /sys directories most Linux distributions also provide a wide variety of command-line tools that you can use to view information about the hardware currently installed in your system.
And if you want to know the truth a lot of these tools actually just pull their information right out of the /proc directly.
Now be aware that many of the commands we’re going to look at here may not actually be installed by default with some distributions.
However, if it’s not installed you can usually go out and get them manually using either the yum or apt-get commands.
Let’s take a look at what some of these utilities are.
3.1 hdparm Command: Get SATA/IDE device parameters
The first one we need to look at is the hdparm command.
It’s used to display information about your hard disk drive, the syntax is to enter hdparm and then specify which hard disk device file we want to view information about.
Syntax: hdparm [options] [device …] / hdparm /dev/device
We would replace this with something like sda or sdb whichever device we want to view information about and when you do data about that device is displayed on the screen.
In this case I’m looking at information about the /dev/sda hard disk drive.
# hdparm /dev/sda
/dev/sda:
SG_IO: bad/missing sense data, sb[]: 70 00 05 00 00 00 00 0a 00 00 00 00 20 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
multcount = 0 (off)
readonly = 0 (off)
readahead = 8192 (on)
geometry = 2610/255/63, sectors = 41943040, start = 03.2 sg_scan Command: Scans SCSI/ATAPI/ATA devices
The next utility you need to be familiar with is the sg_scan utility.
It’s used to scan your scsi buses and list all the devices that are connected to your scsi controllers.
# sg_scan
/dev/sg0: scsi0 channel=0 id=0 lun=0
/dev/sg1: scsi0 channel=0 id=1 lun=0
/dev/sg2: scsi0 channel=0 id=2 lun=0
/dev/sg3: scsi0 channel=0 id=3 lun=0
/dev/sg4: scsi2 channel=0 id=0 lun=0 [em]3.3 sginfo Command: Access mode page information for a SCSI (or ATAPI) device
A similar command is the sginfo -l command.
It’s also used to display information about all the scsi devices in your system.
# sginfo -l
/dev/sg0 [scsi0 ch=0 id=0 lun=0]
/dev/sg1 [scsi0 ch=0 id=1 lun=0]
/dev/sg2 [scsi0 ch=0 id=2 lun=0]
/dev/sg3 [scsi0 ch=0 id=3 lun=0]
/dev/sg4 [scsi2 ch=0 id=0 lun=0]3.4 lsusb Command: List USB devices
Another useful command is the lsusb command.
It displays information about all the USB devices that are currently connected to your system.
When you run it, you can see a listing of all your USB buses and all of the devices that are connected to that bus.
# lsusb
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 002 Device 009: ID 0e0f:0008 VMware, Inc.
Bus 002 Device 003: ID 0e0f:0002 VMware, Inc. Virtual USB Hub
Bus 002 Device 002: ID 0e0f:0003 VMware, Inc. Virtual Mouse
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hubIn this example, I can see that I have two different USB buses, I have Bus 001 and then I have Bus 002.
On Bus 001 all I have is a root hub on Bus 002 I have a root hub and then I have another USB hub and then I have a mouse.
3.5 hwinfo Command: Probe for hardware
Another useful utility is the hwinfo utility.
# hwinfoIt displays a comprehensive overview of all the system hardware in your system.
It will probe the system hardware and then generate a system overview report.
Now if you don’t specify any options with the command it will produce a very long report.
So, what we usually do is limit the report to a single device subsystem using the --device option.
Now you can replace device here with a variety of different types of devices you need to.
Syntax: hwinfo --device
Here is an example, Type the following command to display Network card information.
# hwinfo --short --netcardNote: hwinfo command is not installed by default on a lot of distributions but you can usually go out and get it and install it with yum, zipper or apt-get.
3.6 lspci Command: List all PCI devices
The next command we’re going to look at here is lspci, this lists all of the PCI devices installed with the system.
When you use the -k option then the lspci command will also list the kernel modules associated with each PCI device.
You can see an example of doing that here.
# lspci -k
00:00.0 Host bridge: Intel Corporation 440BX/ZX/DX - 82443BX/ZX/DX Host bridge (rev 01)
Subsystem: VMware Virtual Machine Chipset
00:01.0 PCI bridge: Intel Corporation 440BX/ZX/DX - 82443BX/ZX/DX AGP bridge (rev 01)
00:07.0 ISA bridge: Intel Corporation 82371AB/EB/MB PIIX4 ISA (rev 08)
Subsystem: VMware Virtual Machine Chipset
00:07.1 IDE interface: Intel Corporation 82371AB/EB/MB PIIX4 IDE (rev 01)
Subsystem: VMware Virtual Machine Chipset
Kernel driver in use: ata_piix
Kernel modules: ata_piix, ata_generic
00:07.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 08)
Subsystem: VMware Virtual Machine Chipset
Kernel modules: i2c_piix4
00:07.7 System peripheral: VMware Virtual Machine Communication Interface (rev 10)
Subsystem: VMware Virtual Machine Communication Interface
Kernel driver in use: vmw_vmci
Kernel modules: vmw_vmci3.7 lscpu Command: Display information about the CPU architecture
The lscpu command reports information about the CPU and Processing Units.
# 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: 78
Model name: Intel(R) Core(TM) i5-6300U CPU @ 2.40GHz
Stepping: 3
CPU MHz: 2495.999
BogoMIPS: 4991.99
Hypervisor vendor: VMware
Virtualization type: full
L1d cache: 32K
L1i cache: 32K
L2 cache: 256K
L3 cache: 3072K
NUMA node0 CPU(s): 03.8 lsscsi Command: List SCSI devices
Lists out the SCSI/SATA devices such as hard drives and optical drives.
# lsscsi
[0:0:0:0] disk VMware, VMware Virtual S 1.0 /dev/sda
[0:0:1:0] disk VMware, VMware Virtual S 1.0 /dev/sdb
[0:0:2:0] disk VMware, VMware Virtual S 1.0 /dev/sdc
[0:0:3:0] disk VMware, VMware Virtual S 1.0 /dev/sdd
[2:0:0:0] cd/dvd NECVMWar VMware IDE CDR10 1.00 /dev/sr0 3.9 lsblk Command: List block devices
Lists all block devices, such as the hard drive partitions, Logical Volumes (LVM) and other storage devices like optical drives and flash drives.
# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 20G 0 disk
├─sda1 8:1 0 300M 0 part /boot
├─sda2 8:2 0 2G 0 part [SWAP]
└─sda3 8:3 0 17.7G 0 part /
sdb 8:16 0 3G 0 disk
├─sdb1 8:17 0 500M 0 part
│ └─new_vgroup-newlv001 253:0 0 500M 0 lvm /newlv001
├─sdb2 8:18 0 500M 0 part
│ ├─new_vgroup-newlv001 253:0 0 500M 0 lvm /newlv001
│ └─new_vgroup-newlv002 253:1 0 500M 0 lvm /newlv002
└─sdb3 8:19 0 500M 0 part
└─new_vgroup-newlv002 253:1 0 500M 0 lvm /newlv002
sdc 8:32 0 3G 0 disk
sdd 8:48 0 3G 0 disk
sr0 11:0 1 1024M 0 rom3.10 free Command: Display amount of free and used memory in the system
free Command displays the total amount of free and used physical and swap memory in the system, as well as the buffers and caches used by the kernel. The information is gathered by parsing /proc/meminfo.
# free
total used free shared buff/cache available
Mem: 810492 484516 107052 4480 218924 185472
Swap: 2097148 792320 1304828Conclusion
I hope you have learned something from this article.
I have tried my best to include all the Useful Commands to check System and Hardware Information in Linux
Now I’d like to hear your thoughts.
Was this guide useful to you?
Or maybe you have some queries.
Have I not included any command in this guide?
Leave a comment below.
Source: https://access.redhat.com/
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