System Administrator Blog And Scripts

This article will guide you through how to run the long running command in background without hanging, see the job status and get the output to the file for diagnostic  purpose. We can use nohup and send your long running command to background so that you can continue while the command will keep on executing in the  background . After that you can safely log out. With nohup command we tell the process to ignore the SIGHUP signal which is sent by command on termination, thus making the command persist even after session logout. On session logout the command is detached from the  controlling terminal and keeps on running in the  background as the  daemon process . Executing command using nohup in the  background Here, is a simple scenario wherein, I am trying to restore a big database file in the  background on ssh session using nohup , after which the task was sent to background with prompt returning immediately giv...

System Administrator Scripts: System Administrator Scripts: How to Install ClamA... : System Administrator Scripts: How to Install ClamAV and Configure Daily Scanning on CentOS

System Administrator Scripts: How to Install ClamAV and Configure Daily Scanning on CentOS

How to Install ClamAV and Configure Daily Scanning on CentOS This article will guide you through the installation of ClamAV on CentOS. Once installed, we will also configure a daily scan on our CentOS server. ClamAV is an open source (GPL) antivirus engine designed for detecting Trojans, viruses, malware and other malicious threats on Linux. In this article, we will only be configuring ClamAV to run scheduled/on-demand scans; not resident scans. Install ClamAV 1. Install EPEL repo Before we can do proceed, you must ensure that you have the EPEL yum repository enabled. # rpm -Uvh http://download.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm 2. Install required ClamAV packages # yum install clamav clamd 3. Start the clamd service and set it to auto-start # /etc/ init . d/ clamd start # chkconfig clamd on 4. Update ClamAV’s signatures # /usr/bin/freshclam Note : ClamAV will update automatically, as par...

How to reduce space in LVM and Increase space in LVM Here in this demo I am reducing the 10GB space from lv_home volume and adding this 10GB space to lv_root volume Reduce space in the LVM volume Note: We need to make sure that enough free space is there in the volume where we wanted to reduce the space. other wise we loose the data on the volume. Before doing any thing 1st we needed to un mount the volume # umount /home Needed to check the volume so that we don't loose any data # e2fsck -f /dev/vg_centos/lv_home Run this command to reduce the date here I am reducing 10GB space on volume home for that we needed to resize the volume. # resize2fs /dev/vg_centos/lv_home 10G Then we needed to reduce the space on the # lvreduce -L 10G /dev/vg_centos/lv_home Again check the volume for errors # e2fsck -f /dev/vg_centos/lv_home Mount the volume and check the data. # mount /home Increase the Size of the Vol...

1. Insert the DVD in the laptop/desktop and select boot from CD/DVD,  Select Install CentOS 7 2. Select Install CentOS 7 and press ENTER Loading the required files to the kernel 3. Select English and Click on Continue to proceed. Language selection  4. Select English and Click on Continue to proceed. 5. Click on Installation Source . 6. Select Auto-detected installation media or if you have any source in your network you can specify. 7. Select the type of installation you want, for demo purpose I selected GNOME Desktop and Click DONE . 8. Click on the Installation Destination and Select the Local Standard Disks and Click on Automatically configured partitioning . and Click on DONE . 9. Click on Network & Hostname. 10. Click on ON/OFF to enable the networking while on boot. If you want to configure HOSTNAME or wanted to configure manual settings for network clic...

Docker : Docker is an open source project that automates the deployment of applications  in  inside   Linux Containers, and provides the capability to package an application with its runtime dependencies into a container. Device Hotplug Removed : While RHEL 5/6 has device hotplug support (a udev rule   that runs the   ifup   script for newly created devices), it has been disabled for RHEL 7 since it can result in race conditions when initializing newly found. 32 Bit ISO Image : RHEL 7 will only provide 64-bit ISO's, thus allowing only a 64-bit operating environment. RHEL 7 will not natively support 32-bit hardware. MemAvailable   Added to   meminfo : A new entry to the /proc/meminfo file has been introduced to provide the MemAvailable field.   MemAvailable   provides an estimate of how much memory is available for starting new applications, without swapping. However, unlike the data provided by the Cache...