Visualizzazione degli articoli taggati 'linux'
Steps to grow your KVM VM/Container’s partition after extending root OS size or extending...
Steps to grow your KVM VM/Container’s partition after extending root OS size or extending...
The command-line tool firewall-cmd is part of the firewalld application, which is installed by...
Use the journalctl command to view the journal logs. By default, the listed entries include a...
Linux is a multitasking, multi-user system that allows all the processes to run simultaneously...
The main configuration file for Apache is /etc/httpd/conf/httpd.conf. Apache runs as installed,...
Apache containers are special configuration directives that group other directives. The...
Apache HTTP server The Apache HTTP Server, an open-source web server developed by the Apache...
Dynamic Host Configuration Protocol (DHCP) allows client machines to automatically obtain network...
The Linux kernel is loaded into memory by the boot loader. Kernel modules are dynamically loaded...
Maintaining Software Using RPM (Red Hat Package Manager) RPM is a powerful software manager...
A Network File system (NFS) allows a server to share directory hierarchies (file systems) with...
Samba is an open-source implementation of the Server Message Block (SMB) protocol. It allows...
Swap space is used in Linux when there is insufficient physical memory (RAM) on your system to...
File Transfer Protocol (FTP) is a commonly used method of downloading and uploading files between...
The Linux system log daemon is responsible for logging system messages. Starting RHEL 6, The...
The GRUB2 configuration file /boot/grub2/grub.cfg – Starting RHEL 7 GRUB 2 is the bootloader....
Kdump is the Linux kernel crash dumping mechanism. In the event of a system crash, Kdump provides...
The FTP service/server is provided by the vsftpd daemon. Very Secure FTP Daemon (vsftpd) is the...
sysctl parameter didn’t take effect after a reboot on RHEL 7 server. Parameter...
The SMB service is unable to start, SAMBA shares can’t be accessed. Using systemctl fails to...
While starting or restarting the vsftpd service you might get below error on an RHEL 7 system. #...
Kdump is the Linux kernel crash dumping mechanism. In the event of a system crash, Kdump provides...
For the purpose of this post, let’s assume that you do not have any swap configured on your...
YUM (Yellowdog Updater, Modified) provide more services and functionality than is available with...
Due to application certification and other restrictions in a production environment, it may be...
By default, the LVM configuration does not allow you to log the commands that are used in a shell...
The default configuration of the /etc/named.conf file provides a caching-only nameserver. The...
While formatting a USB disk which was mounted in write-protected mode we are getting the below...
If you know the proper commands, File Management becomes easier. Following are the basic Linux...
Popular port numbers in Linux HTTP – TCP 80 HTTPS – TCP 443 POP3 – TCP 110 SMTP – TCP 25 SSH...
The failure in finding the easiest and yet more practical means of looking up files is one of the...
cPanel only LVE Manager inodes Limits extension allows you to set inodes limits for your...
We may want to add some swap space for a Linux box while only find that all disk space is...
To add a new user to access a samba share you need to first create a server user account using...
After installation and start of the VSFTPD service, two files are created in the /etc/vsftpd/...
Below example shows how to create a systemd script to mount a disk under a specific path on...
Use the xfsdump and xfsrestore utilities to back up and restore files in an XFS file system. You...
When there is an issue with booting up RHEL / CentOS 7 system you can boot it into rescue mode...
You have a system configured with hugepages and you want to find per-process hugepages...
The 2 environment variables which majorly affects the Bash History setting of saving the last run...
Removing the rhgb and the quiet kernel command-line parameters, either by editing the...
Hard disks can fail unexpectedly and it is always best to keep recent backups of all important...
Device temperature control is, therefore, significant. Most of the time, your laptop computer...
A directory is nothing but a location for storing files on the Linux system in a hierarchical...
One can use the Ubuntu Linux command line or terminal app to display a running process, change...
To manage processes from the Ubuntu terminal The ps command is a traditional Ubuntu Linux...
Previous versions of CentOS/RedHat Linux use init scripts located in the /etc/rc.d/init directory...
For some operations (for example, a yum install operation), Yum downloads the packages to install...
Are you facing a performance issue and you suspect it might be related to cache usage? High cache...
Traditional Linux access permissions for files and directories consist of setting a combination...
Caching-only nameservers, or recursive nameservers, offer resolution services but they are not...
The procedure to configure DM-Multipath from an iSCSI initiator to an iSCSI target is presented,...
HugePages is a feature integrated into the Linux kernel with release 2.6. This feature basically...
Internet Small Computer System Interface (iSCSI) is an IP-based standard for connecting storage...
Internet Small Computer System Interface (iSCSI) is an IP-based standard for connecting storage...
Multicast can be used to send IP packets to a group of interested receivers. Compared with...
The Network Time Protocol (NTP) enables the accurate dissemination of time and date information...
A VLAN is a type of local area network that does not have its own dedicated physical...
btrfs or Butter FS is a filesystem and has some interesting features: One can have FS...
Here is a short howto on creating a new /boot partition in LVM and migrate the existing boot...
Btrfs is an open-source, general-purpose file system for Linux. The name derives from the use of...
In RHEL 5 and 6, we were using automatic startup feature of RHEL through /etc/rc.d/init.d to run...
In most of the situations you would simply create a loopback device using “losetup” and mount it...
Linux supports a special block device called the loop device, which maps a normal file onto a...
The post list out the steps to delete a disk partition using fdisk command. Please note the...
Internet Small Computer System Interface (iSCSI) is an IP-based standard for connecting storage...
A CPU is an acronym for the central processing unit. It is an essential part of a computer. The...
Upon system bootup there should be a single tty console running Xorg on it. New tty consoles are...
To disallow the loading of malicious or unwanted modules, we can blacklist them. In order to...
You can disable the cache by adding the following to the .htaccess <Files...
By default, RHEL 7 uses the FirewallD service to provide network security. Firewalld may not be...
We have already seen how to disable ipv6 globally on CentOS / RHEL 7. There could be an ask to...
Non-Uniform Memory Access or Non-Uniform Memory Architecture (NUMA) is a physical memory design...
If you check the ‘ifconfig -a’ after a fresh install of RHEL/CentOS 6,7 system, you would find...
Explicit Huge Pages V/s Transparent Huge Pages There can be two types of HugePages in the...
A cron job is a Linux command used for scheduling tasks to be executed sometime in the future....
Bind query logging can be very handy if you are troubleshooting a problem. However, it generates...
XFS supports disk quotas by user, by group, and by project. Project disk quotas allow you to...
IPv6 is enabled by default on RHEL / CenOS 7 systems. So, if IPv6 was disabled on the system...
GDM can be configured to allow remote access via XDMCP (X Display Manager Control Protocol). We...
In CentOS/RHEL 7, the /etc/pam.conf is depreciated and /etc/pam.d/remote will be used for...
At boot time (or whenever a network driver is loaded) interfaces are always assigned ethX style...
The main configuration file for VSFTPD is ‘/etc/vsftpd/vsftpd.conf‘. When verbose logging is...
To enable X11 Forwarding on a server client edit the file “/etc/ssh/ssh_config” and on ssh server...
There are three ways to restrict number of CPU’s in CentOS/RHEL. Using maxcpus parameter...
A loopback device is used to access filesystems that are not associated with a block device (Hard...
The post outlines the steps to extend the last partition of the disk and the filesystem residing...
In some situations, you need to change the VLAN IP address such as 172.0.0.2 with 172.0.0.1 for...
The Central Processing Unit (CPU) is considered an essential component in any system. It is known...
Non-Uniform Memory Access or Non-Uniform Memory Architecture (NUMA) is a physical memory design...
Find out BIOS version, run: # dmidecode | less $ sudo dmidecode | less How to check BIOS...
If the home directory, say /home, is a filesystem (mount point), then you could use df. If it's...
With the introduction of systemd in RHEL 7 the boot process has become a lot faster because many...
This article will help you how to recursively dig into directories to find and list all files...
Use the xfs_growfs command to increase the size of an XFS file system. The XFS file system must...
I am a new Linux user. How do I hide files and directories in Linux operating systems using the...
To provide printer and file sharing, Microsoft Windows uses a facility known as SMB (Server...
The sosreport tool collects information about a system, such as hardware configuration, installed...
It’s not recommended to use telnet as it is not secure. The passwords are transferred using a...
Virtual Network Computing (VNC) works by capturing the display’s frame buffer and making it...
Ansible is an open source and free configuration management IT tool. It is similar to Chef or...
FFmpeg is an open source and free software for managing video, audio, and other multimedia files...
Let us see all steps and command in details. Alpine Linux install htop Let us search for...
A situation where the system has no kernel to boot from maybe because all the kernel are removed...
You can download software by visiting this page . However, Fedora Linux includes software in its...
Open VM Tools (OVT) consists of a suite of virtualization utilities that improves the...
Scout_Realtime is a simple, easy-to-use web-based tool for monitoring Linux server metrics in...
Introduction – Oracle VirtualBox is an open source and free hypervisor/virtual machine monitor...
The user wants to see the list of commands used in the syslog messages. This way the user can...
Any change made with the ethtool program does not persist across reboots or network module...
Sometimes, to troubleshoot some multipath related issues, you would require to map the...
Starting RHEL 7, GRUB2 is the default boot loader. The configurations and settings of GRUB2 are...
In our environment, we have duplicate initiator id in /etc/iscsi/initiatorname.iscsi due to...
A TCP/IP network connection may be either blocked, dropped, open, or filtered. These actions are...
Use the following curl command: curl -I url curl -I curl -I...
The requirement here is that the user should not use the last 10 used passwords again when...
The purpose of this post is to explain how to configure kernel parameters on Red Hat...
For any reason, if the yum transaction was interrupted before it could complete, you would get an...
Why rpm database gets corrupted There can be multiple reasons which can lead to rpm database...
The ‘root’ entry was removed from /etc/shadow and /etc/passwd. How to recover the deleted root...
If you have a secure certificate (SSL) on your website, you can automatically redirect visitors...
CentOS / RHEL 7 now includes GRUB2 which uses a new way of installing to the MBR of your boot...
To remove the default rescue image that gets installed when you install a CentOS/RHEL 7 system....
There is only one Network card on machine but ifconfig shows 2 interface by name virbr0 and...
The mv command (mv source target) renames the file/folder named by the source operand to the...
It is a common task to resize/expand btrfs file system since btrfs is widely used in CentOS/RHEL...
LVM takes a backup of the on-disk metadata before and after running any LVM operation on a...
So the requirement here is, we do not want to run MariaDB as the mysql user and group which is...
RHEL 7 offers another utility to configure and display date and time information, timedatectl....
This post outlines how a Linux System administrator can limit the allowed number of processes for...
Udev is the mechanism used to create and name /dev device nodes corresponding to the devices that...
The Apache web servers highly support customization and can be configured in multiple ways to...
1. Check the attributes of the FC remote port(s) using the below command: # udevadm info...
Dynamic Host Configuration Protocol (DHCP) allows client machines to automatically obtain network...
It is possible to limit bandwidth used by yum while downloading package updates using throttle...
Internet Small Computer System Interface (iSCSI) is an IP-based standard for connecting storage...
The nfsiostat command works like the iostat command except only for the NFS mount points. The...
Btrfs is a filesystem which is very new and is still under development and benchmarking phase. As...
Did you want MySQL to turn off Binary logging in MySQL? The below article explains an easy way to...
Fedora Linux 30 released. This page shows how to use dnf system upgrade to upgrade your system to...
The iperf is a tool used for testing the network performance between two systems. The iperf...
SysRq utility In case your kernel freezes or/and hangs, you can use ‘magic’ SysRq tool. The...
The rndc utility is a command-line tool to administer the named service, both locally and from a...
“repoquery” is a program for querying information from YUM repositories similarly to rpm queries....
Use the xfs_admin command to change the parameters of an XFS file system. You can also use the...
When i installed a new version of the Java Runtime Environment but the “java -version” command...
Chromium is a free and open source software created by Google. Chromium act as the upstream...
CentOS 7 install Google Chrome Use wget command to grab Google Chrome 73 installer, run: $...
Here is a short note on List of Commands to Install Security Vulnerabilities with yum. To get...
Let us see how to stop and disable Firewalld on a CentOS or RHEL 7.x based system. Is...
This post lists some of the more commonly used command-line utilities for managing and operating...
The best tool for maintaining file systems is fsck, which checks and repairs Linux file systems....
When trying to start MySQL using systemctl fails to start, for example: # systemctl status...
Lightweight Directory Access Protocol (LDAP) is used to access centrally stored information over...
So, here is the situation – pvcreate and vgcreate command throws errors shown below. # pvcreate...
pvcreate command fails while using multipath device with below error even when the device is...
The XFS File system is a high-performance journaling file system. XFS supports a maximum file...
Below is a sample /etc/multipath.conf file taken from CentOS 7.4, from the directory...
TCP wrappers are capable of more than allowing and denying access to services. With the optional...
Internet Small Computer System Interface (iSCSI) is an IP-based standard for connecting storage...
The "ps" command in Linux is an abbreviation of "process status". It is used to get information...
The mtr(my traceroute) command, originally named Matt's traceroute, is a computer program that...
UNIX/Linux operating systems have the ability to limit the number of various system resources...
The xinetd daemon is a TCP wrapped super service which controls access to a subset of popular...
xinetd daemon The xinetd daemon is a TCP wrapped super service which controls access to a subset...
As the name implies, a chroot operation changes the apparent root directory for a running process...
The multipathd daemon checks for failed paths and reconfigures the multipath map. The daemon runs...
By default, multipath devices are identified by a World Wide Identifier (WWID), which is globally...
Information about domains in the DNS database is stored in zone files. A zone file consists of...
Internet Small Computer System Interface (iSCSI) is an IP-based standard for connecting storage...
The configuration file for Kdump is /etc/kdump.conf. The default target location for the vmcore...
The multipath utility is the device mapper target auto-configurator, which is used to detect and...
RPM is a powerful software manager which can be used to build, install, query, verify, update,...
The following list summarizes the command-line utilities included with the Samba packages. Use...
A given SELinux policy can be customized by enabling or disabling a set of policy Booleans....
The SELinux policy describes the access permissions for all users, programs, processes, files,...
TCP wrappers provide basic traffic filtering of incoming network traffic. Access to “wrapped”...
The main configuration file for DM-Multipath is /etc/multipath.conf. This file is not created by...
In addition to /proc, the kernel also exports information to another virtual file system called...
Samba Server type is configured in the [global] section of the /etc/samba/smb.conf file. Below...
SELinux Modes SELinux runs in one of three modes (or states). Enforcing This is the default...
There are SELinux users in addition to the regular Linux users. SELinux users are part of an...
Network interface bonding is called by many names: Port Trunking, Channel Bonding, Link...
GoAccess is an interactive and real-time web server log analyzing programmer that instantly...
Rocky Linux is one of the Linux distributions, and it is also based on Red Hat Enterprise Linux...
Here is a short note, if you are looking for packages (RPM) for Oracle ASMLib (oracleasm) for...
In CentOS/RHEL 7, tmpfiles.d cleans up /tmp or /var/tmp by removing unused files. This function...
While issuing any yum command, you would get an error shown below: # yum list Loaded plugins:...
ip command provided by the iproute package is used to adjust addresses, link state, routing...
Btrfs is an open-source, general-purpose file system for Linux. The name derives from the use of...
Mounting the nfs share from CentOS/RHEL NFS server on a NFS client gives error as shown below: #...