LTIMindtree Linux Administrator Interview Questions and Answers

To troubleshoot a server that booted up with the old kernel after a new kernel update, check the bootloader configuration, verify the kernel installation, and review the update process.

• Check the bootloader configuration to ensure it is pointing to the correct kernel version.

• Verify the kernel installation to see if the new kernel was successfully installed.

• Review the update process to identify any errors or issues that ...read more

Various commands to check CPU and Memory utilization in Linux server.

• To check CPU utilization: top, mpstat, sar

• To check Memory utilization: free, vmstat, sar -r

To add a new disk to the system using LVM, you need to initialize the disk, create a physical volume, extend the volume group, and finally extend the logical volume.

• Initialize the disk using fdisk or parted command

• Create a physical volume using pvcreate command

• Extend the volume group using vgextend command

• Extend the logical volume using lvextend command

• Resize the filesystem using resize2fs or xfs_growfs command

Experienced Linux Administrator with a passion for troubleshooting and optimizing systems.

• Over 5 years of experience managing Linux servers in a corporate environment

• Skilled in shell scripting, server configuration, and system monitoring tools like Nagios

• Strong problem-solving skills and ability to work well under pressure

• Certified in Red Hat Enterprise Linux (RHCE)

• Passionate about staying up-to-date with the latest te

Some additional skills I possess include scripting languages, troubleshooting abilities, and strong communication skills.

• Proficiency in scripting languages such as Python, Bash, or Perl can be beneficial for automating tasks and improving efficiency.

• Strong troubleshooting abilities are essential for quickly identifying and resolving issues that may arise in a Linux environment.

• Effective communication skills are importa...read more

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

ACL stands for Access Control List, a set of permissions attached to an object that specifies which users or system processes are granted access to that object.

• ACLs are used to control access to files, directories, and other resources on a system.

• They define who can read, write, or execute a file or directory.

• ACLs can be set on a per-user or per-group basis, allowing for more granular control over access permissions.

• Ex...read more

LVM (Logical Volume Manager) is a tool used in Linux to manage storage by creating logical volumes from physical volumes.

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

• It provides features like snapshots, striping, mirroring, and thin provisioning.

• Physical volumes are divided into extents, which can be allocated to logical volumes.

• Commands like pvcreate, vgcreate, lvcreate are used to create physic...read more

To schedule a cron job, use the crontab command to edit the cron table file.

• Use the crontab -e command to open the cron table file for editing

• Add a new line to the file with the schedule timing and the command to be executed

• Save and exit the file to schedule the cron job

Sticky bit is a permission in Unix/Linux that allows only the owner of a file to delete or rename it.

• Sticky bit is represented by a 't' in the permissions of a file or directory.

• When the sticky bit is set on a directory, only the owner of a file within that directory can delete or rename the file.

• Commonly used on directories like /tmp to prevent users from deleting each other's files.

• Example: chmod +t directory_name

File system integrity can be checked using fsck command in Linux.

• Use fsck command to check and repair file system errors

• Run fsck on unmounted file systems for accurate results

• Use options like -y to automatically repair errors without user intervention