HCL Group Linux Administrator Interview Questions, Process, and Tips

LVM stands for Logical Volume Manager, a tool used to manage disk storage in Linux systems.

• LVM allows for dynamic resizing of logical volumes without downtime.

• It consists of physical volumes, volume groups, and logical volumes.

• Commands like pvcreate, vgcreate, lvcreate are used to create and manage LVM.

• LVM provides flexibility in managing storage space by allowing logical volumes to span multiple physical disks.

To mount NFS, use the 'mount' command with the NFS server IP address and the mount point on the local machine.

• Use the 'mount' command followed by the NFS server IP address and the mount point on the local machine

• For example: sudo mount 192.168.1.100:/shared_folder /mnt/nfs_share

• Ensure that the NFS server is properly configured and accessible from the local machine

Patching involves applying updates to software to fix vulnerabilities and improve performance.

• Identify the software that needs to be patched

• Download the appropriate patches from the vendor's website

• Test the patches in a non-production environment before applying them to production systems

• Schedule downtime for applying patches to minimize disruption

• Document the patching process for future reference

To rollback a package, use package manager to uninstall current version and install previous version.

• Use package manager to uninstall current version of the package

• Install the previous version of the package using package manager

• Check for any dependencies that may need to be rolled back as well

To remove older kernels in Linux, use package management tools like apt or yum.

• Use 'apt autoremove' command in Debian-based systems to remove old kernels

• Use 'yum remove ' command in Red Hat-based systems to remove old kernels

• Check available kernels with 'uname -r' command before removing

Grant SFTP access exclusively to user David

• Create a new group specifically for David, e.g. 'davidgroup'

• Set the ChrootDirectory in the SSH configuration file to restrict David's access to a specific directory

• Add David to the 'davidgroup' and configure the necessary permissions for SFTP access

To lock a user out after 6 unsuccessful password attempts for 30 minutes, modify the PAM configuration file.

• Edit the PAM configuration file (/etc/pam.d/common-auth) to include the 'pam_tally2' module.

• Set the 'deny' option in the 'pam_tally2' module to lock the user out after 6 failed attempts.

• Specify the 'unlock_time' option in the 'pam_tally2' module to set the duration of the lockout period to 30 minutes.

• Example: aut

NFS can be configured by setting up the NFS server, exporting directories, and configuring client access.

• Install NFS server package on the server

• Edit /etc/exports file to specify directories to be shared

• Restart NFS service to apply changes

• Configure client access by mounting NFS shares on client machines

Patching involves applying updates to software to fix vulnerabilities and improve performance.

• Identify the software that needs to be patched

• Download the necessary patches from the vendor's website

• Test the patches in a non-production environment before applying them to production systems

• Schedule a maintenance window to apply the patches

• Apply the patches using tools like yum, apt-get, or Windows Update

• Verify that the pat...read more