Enable Password based authenticaiton in OCI compute instance

If you want to use a password to access the SSH server, a solution for fixing the Permission denied error is to enable password login in the sshd_config file.

To do this, open the file in a text editor.  This example uses the nano editor:

sudo nano /etc/ssh/sshd_config

In the file, find the PasswordAuthentication line and make sure it ends with yes.

Find the ChallengeResponseAuthentication option and disable it by adding no.

If lines are commented out, remove the hash sign # to uncomment them. Save the file and exit. Restart the SSH service by typing the following command:

sudo systemctl restart sshd
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Multipart Upload on OCI Bucket / Object Storage using OCI-CLI in Windows or Linux

Oracle OCI-CLI requires Python packages v 3.6 or higher. During installation it is auto installed on windows server/OS, however on Linux, there might be preinstalled Python package installed, that might need to be updated manually before running the installer. (In few cases, the installation failed and the package needed to be be updated seperately)

Installation on Linux

bash -c "$(curl -L https://raw.githubusercontent.com/oracle/oci-cli/master/scripts/install/install.sh)"

For CentOS-7 few additional steops might needed-

sudo yum groupinstall 'Development Tools'
sudo yum install centos-release-scl
sudo yum install rh-python36
scl enable rh-python36 bash
yum -y install python-pip

afterwards, run the installer command mentioned above. Continue reading “Multipart Upload on OCI Bucket / Object Storage using OCI-CLI in Windows or Linux” »

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Posted in OCI.

MikroTik Router SNMP Configuration

First, you need to access the console of your MikroTik router. On the prompt screen, enter the administrative login information. Factory default access information:

  • Username: admin
  • Password: (No password)

After a successful login, the console command-line will be displayed. Use the following command to enable the SNMP service on the MikroTik router.
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[admin@MikroTik] > snmp set enabled=yes

Use the following command to list the snmp communities available on the MikroTik router.

[admin@MikroTik] > snmp community print
Flags: * - default
# NAME ADDRESSES SECURITY READ-ACCESS
0 * public ::/0 none yes

As you can see, Mikrotik has a default SNMP community named PUBLIC.

The PUBLIC SNMP comminity has the ID number 0.

Use the following command to rename the PUBLIC snmp community. Continue reading “MikroTik Router SNMP Configuration” »

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Creating a XEN guest and tidbids in CLI

INSTALLING A GUEST DOMAIN (“DOMU”)

Now that the Xen hypervisor/Dom0 virtual machine is configured and up and running, it’s time to configure and create a DomU. Just like we did in the Debian 9 tutorial, we will now install and use the xen-tools package to automate the steps involved in creating a paravirtualized (“PV”) DomU.

INSTALL DEBIAN PACKAGE XEN-TOOLS

Use apt-get to update the Xen hypervisor/Dom0 package index files, and upgrade all currently installed packages. As root run the following command:

# apt-get update && apt-get upgrade

Next, use apt-get to install the xen-tools package from the Debian stretch repository, which is currently shipping xen-tools version 4.8-1. Run the following command as root:

# apt-get install xen-tools

SET UP NEW PARTITION AND VOLUME GROUP

Before we use xen-tools to create a new DomU, we need to create a LVM volume group which will be used to provision disk space for new virtual machines. In this step, we assume Dom0 was installed on the /dev/sda1 partition of your primary disk drive, and that all other /dev/sda drive space is empty. Continue reading “Creating a XEN guest and tidbids in CLI” »

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Cloudmin-GPL XEN on Debian 10

This article is inspired and prepared on the forked Cloudmin Xen script updated for Debian 10. However, the following procedures to be followed as precuationary before executing the updated script, which is available in this post in below section.

PHASE-I Prepare Environment for XEN

INSTALLING THE XEN HYPERVISOR AND HOST/CONTROL DOMAIN (“DOM0”)

In this step we install the Xen Project hypervisor software package, and configure the Dom0 virtual machine by way of the Debian base operating system. Once all preliminary configuration is complete, we will reboot the computer and automatically boot into the Xen hypervisor/Dom0 virtual machine to explore the new system.

INSTALL XEN HYPERVISOR

If you need to add a non-root user, the sudo package, non-free firmware, a firewall, or other necessary packages, now is the time.

Use apt-get to update the Debian base operating system package index files, and upgrade all currently installed packages. As root (or using sudo) run the following command:

# apt-get update && apt-get upgrade

Next, use apt-get to install the Xen Project hypervisor meta-package. Run the following command as root, adjusting the architecture suffix to suit your hardware: Continue reading “Cloudmin-GPL XEN on Debian 10” »

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Reset Webmin Password

  1. Open a terminal or command prompt on the server where Webmin is installed.
  2. Navigate to the Webmin installation directory. The default location is
    /usr/local/webmin
    cd /usr/local/webmin
  3. To change password run command:on RedHat distributions (i.e. Fedora, CentOS, Gentoo, etc.):
    /usr/libexec/webmin/changepass.pl /etc/webmin admin newPassword
  4. on Debian distributions (i.e. Debian, Ubunto, etc.):
    /usr/share/webmin/changepass.pl /etc/webmin admin newPassword
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Disable Last Login Message on Linux using hushlogin

Single user

To permanently suppress a Last Login message as per on user basis, create a hidden .hushlogin file inside a user’s home directory. For example to suppress a Last Login message for the linuxconfig user, we would run this command:

$ sudo touch /home/linuxconfig/.hushlogin

Similarly to suppress a Last Login message for the root user, we would run this command: Continue reading “Disable Last Login Message on Linux using hushlogin” »

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Create a local ISO SR at XCP-NG

From the CLI:

  1. Create a directory on the local filesystem to storage your ISOs
  2. Copy/move ISOs to this new location
  3. Create the ISO SR using xe sr-create
  4. You can add or update ISOs later by placing them into the directory you created in step 1
  5. Rescan the SR if you change the files stored in the ISO directory

Continue reading “Create a local ISO SR at XCP-NG” »

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