Databases, Systems & Networks

Source: BinaryTides

Hardware information

Like for every thing, there are plenty of commands to check information about the hardware of your linux system. Some commands report only specific hardware components like cpu or memory while the rest cover multiple hardware units.

This post takes a quick look at some of the most commonly used commands to check information and configuration details about various hardware peripherals and devices. The list includes lscpu, hwinfo, lshw, dmidecode, lspci etc.

1. lscpu

The lscpu command reports information about the cpu and processing units. It does not have any further options or functionality.

$ lscpu
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                4
On-line CPU(s) list:   0-3
Thread(s) per core:    1
Core(s) per socket:    4
Socket(s):             1
NUMA node(s):          1
Vendor ID:             GenuineIntel
CPU family:            6
Model:                 23
Stepping:              10
CPU MHz:               1998.000
BogoMIPS:              5302.48
Virtualization:        VT-x
L1d cache:             32K
L1i cache:             32K
L2 cache:              2048K
NUMA node0 CPU(s):     0-3

2. lshw – List Hardware

A general purpose utility, that reports detailed and brief information about multiple different hardware units such as cpu, memory, disk, usb controllers, network adapters etc. Lshw extracts the information from different /proc files.

$ sudo lshw -short

H/W path        Device      Class       Description
===================================================
                            system      ()
/0                          bus         DG35EC
/0/0                        processor   Intel(R) Core(TM)2 Quad CPU    Q8400  @ 2.66GHz
/0/0/1                      memory      2MiB L2 cache
/0/0/3                      memory      32KiB L1 cache
/0/2                        memory      32KiB L1 cache
/0/4                        memory      64KiB BIOS
/0/14                       memory      8GiB System Memory
/0/14/0                     memory      2GiB DIMM DDR2 Synchronous 667 MHz (1.5 ns)
/0/14/1                     memory      2GiB DIMM DDR2 Synchronous 667 MHz (1.5 ns)
/0/14/2                     memory      2GiB DIMM DDR2 Synchronous 667 MHz (1.5 ns)
/0/14/3                     memory      2GiB DIMM DDR2 Synchronous 667 MHz (1.5 ns)
/0/100                      bridge      82G35 Express DRAM Controller
/0/100/2                    display     82G35 Express Integrated Graphics Controller
/0/100/2.1                  display     82G35 Express Integrated Graphics Controller
/0/100/19       eth0        network     82566DC Gigabit Network Connection
/0/100/1a                   bus         82801H (ICH8 Family) USB UHCI Controller #4
/0/100/1a.1                 bus         82801H (ICH8 Family) USB UHCI Controller #5
/0/100/1a.7                 bus         82801H (ICH8 Family) USB2 EHCI Controller #2
/0/100/1b                   multimedia  82801H (ICH8 Family) HD Audio Controller
/0/100/1c                   bridge      82801H (ICH8 Family) PCI Express Port 1
/0/100/1c.1                 bridge      82801H (ICH8 Family) PCI Express Port 2
/0/100/1c.2                 bridge      82801H (ICH8 Family) PCI Express Port 3
/0/100/1c.2/0               storage     JMB368 IDE controller
/0/100/1d                   bus         82801H (ICH8 Family) USB UHCI Controller #1
/0/100/1d.1                 bus         82801H (ICH8 Family) USB UHCI Controller #2
/0/100/1d.2                 bus         82801H (ICH8 Family) USB UHCI Controller #3
/0/100/1d.7                 bus         82801H (ICH8 Family) USB2 EHCI Controller #1
/0/100/1e                   bridge      82801 PCI Bridge
/0/100/1e/5                 bus         FW322/323 [TrueFire] 1394a Controller
/0/100/1f                   bridge      82801HB/HR (ICH8/R) LPC Interface Controller
/0/100/1f.2                 storage     82801H (ICH8 Family) 4 port SATA Controller [IDE mode]
/0/100/1f.3                 bus         82801H (ICH8 Family) SMBus Controller
/0/100/1f.5                 storage     82801HR/HO/HH (ICH8R/DO/DH) 2 port SATA Controller [IDE m
/0/1            scsi3       storage     
/0/1/0.0.0      /dev/sda    disk        500GB ST3500418AS
/0/1/0.0.0/1    /dev/sda1   volume      70GiB Windows NTFS volume
/0/1/0.0.0/2    /dev/sda2   volume      395GiB Extended partition
/0/1/0.0.0/2/5  /dev/sda5   volume      97GiB HPFS/NTFS partition
/0/1/0.0.0/2/6  /dev/sda6   volume      97GiB Linux filesystem partition
/0/1/0.0.0/2/7  /dev/sda7   volume      1952MiB Linux swap / Solaris partition
/0/1/0.0.0/2/8  /dev/sda8   volume      198GiB Linux filesystem partition
/0/3            scsi4       storage     
/0/3/0.0.0      /dev/cdrom  disk        DVD RW DRU-190A

Check out the following post to learn more about lshw

Get hardware information on Linux with lshw command

Lire la suite…

“inotify”, Remplaçant de “dnotify”, est une technologie, intégrée au noyau Linux (>=2.6.13) , destinée à notifier les événements, modifications, accès, etc, effectués sur le contenu d’un système de fichiers en ce basant sur le contrôle des “inodes” (structures de données contenant des informations sur les fichiers d’un systèmes de fichiers).

« incron« , Pour « INotify CRON », permet d’exploiter les informations « d’inotify » afin d’effectuer une action, commande(s), scripts, etc, en cas de modifications de fichiers ou de répertoires donnés.

Installation de inotify

« inotify » Est intégré au noyau et est activé dans les kernels fournis par les distributions.

« incron » Est, de son côté, empaqueté sur la plupart des distributions mais nécessitera, sur Red Hat et ses dérivées (CentOS, Scientific Linux, etc) l’ajout des miroirs EPEL (« Extra Packages for Enterprise Linux » voir « Ajout des miroirs EPEL (Extra Packages for Enterprise Linux) sous Red Hat like (CentOS, RHEL, SL, …) » sur Admin Linux). L’installation s’effectue via le gestionnaire de paquet de votre distribution.

Sous Ubuntu, Debian et ses dérivés :

# apt-get install incron

Sous les dérivés de Red Hat :

# yum install incron

Sous Gentoo Linux « emerge » se chargera de l’installation tous comme « pacman » le fera très bien sous Arch Linux.

Lire la suite…

L’organisation de votre répertoire personnel ou même de votre système peut être particulièrement difficile si vous avez l’habitude de télécharger toutes sortes de choses sur Internet.

Souvent, vous constaterez que vous avez téléchargé le même mp3, pdf, epub (et toutes sortes d’autres extensions de fichiers) et que vous l’avez copié dans différents répertoires. Cela peut encombrer vos répertoires de toutes sortes de choses dupliquées inutiles.

Dans ce didacticiel, vous allez apprendre à rechercher et à supprimer des fichiers en double sous Linux à l’aide des outils de ligne de commande rdfind et fdupes, ainsi qu’à l’aide d’outils d’interface graphique appelés DupeGuru et FSlint.

Une note de prudence – faites toujours attention à ce que vous supprimez sur votre système car cela peut entraîner une perte de données indésirable. Si vous utilisez un nouvel outil, essayez-le d’abord dans un répertoire de test où la suppression de fichiers ne posera pas de problème.

Rdfind – Trouve les fichiers en double sous Linux

Rdfind provient de la recherche de données redondantes. C’est un outil gratuit utilisé pour trouver des fichiers en double dans ou dans plusieurs répertoires. Il utilise la somme de contrôle et trouve les doublons basés sur le fichier contient non seulement des noms. Lire la suite…

weather-forecast-command-line-finger-graph

Checking weather: purpose of the command

There’s no shortage of methods to retrieve a weather report, the web is full of weather resources, everyones iPhone, Apple Watch, and smartphone has a weather app, Siri can tell you the weather, and you can even get the current weather in the menu bar of OS X or from Spotlight on the Mac too.

But for command line users, none of those options are particularly ideal, since it means leaving the command line and the task at hand.

Thanks to an interesting usage of the finger utility, you can quickly retrieve a weather report and weather forecast for virtually any city in the world, right from the command line.

With this trick you’ll see the temperature forecast (in celsius) for the day, wind direction and wind speed, precipitation and precipitation type (rain, showers, sleet, snow, etc), depth of precipitation, and more. This works with any command line that has the finger tool, whether you’re in Mac OS X, linux, BSD, Windows, it doesn’t matter, it will work the same.

To try this out yourself on the Mac, launch the OS X Terminal found in /Applications/Utilities/ and type the following command syntax:

finger (city name)@graph.no

For example, to get the weather forecast for Montreal Canada, you would use the following syntax at the command line:

finger [email protected]

Lire la suite…

Remote Linux Commands

You would like to execute a command on a remote Linux/FreeBSD/Solaris/UNIX host and have the result displayed locally. Once result obtained it can be used by local script or program. A few examples:
=> File system and disk information

=> Get user information

=> Find out all running process

=> Find out if particular service is running or not etc

You can use rsh or ssh for this purpose. However, for security reason you should always use the ssh and NOT rsh. Please note that remote system must run the OpenSSH server.

Syntax for running command on a remote host:
ssh [USER-NAME]@[REMOTE-HOST] [command or script]

Where,

• ssh: ssh (SSH client) is a program for logging into a remote machine and for executing commands on a remote machine.
• USER-NAME: Remote host user name.
• REMOTE-HOST: Remote host ip-address or host name, such as my-site.com.
• command or script: Command or shell script is executed on the remote host instead of a login shell.

Examples

(A) Get disk information from a server called my-site.com:
$ ssh [email protected] df -h

(B) List what ports are open on remote host
$ ssh [email protected] netstat -vatn

(C) Reboot remote host:
$ ssh [email protected] reboot

(D) Restart mysql server (please note enclosed multiple command line arguments using a single or double quotes)
$ ssh [email protected] '/etc/init.d/mysql restart'

(E) Get memory information and store result/output to local file /tmp/memory.status:
$ ssh [email protected] 'free -m' > /tmp/memory.status

(G) You can also run multiple command or use the pipes, following command displays memory in format of « available memory = used free memory » :
$ ssh [email protected] free -m | grep "Mem:" | awk '{ print "Total memory (used free): " $3 " " $4 " = " $2 }'

See how to configure ssh for password less login using public key based authentication.

=> Related: shell script to get uptime, disk usage, cpu usage, RAM usage, system load, etc. from multiple Linux servers and output the information on a single server in a html format.

Source: NixCraft