10 HP-UX Interview Questions and Answers

HP-UX, Hewlett-Packard’s proprietary Unix operating system, is known for its robustness, scalability, and security features. It is widely used in enterprise environments for mission-critical applications, offering high availability and performance. With its advanced file system management, virtualization capabilities, and comprehensive security features, HP-UX remains a preferred choice for many organizations.

This article provides a curated selection of interview questions designed to test your knowledge and proficiency in HP-UX. By reviewing these questions and their detailed answers, you will be better prepared to demonstrate your expertise and problem-solving abilities in a technical interview setting.

HP-UX Interview Questions and Answers

1. Explain the boot process.

The boot process of HP-UX involves several stages:

• Firmware Initialization: When the system powers on, the firmware (PDC – Processor Dependent Code) initializes hardware components and performs self-tests.
• Boot Loader: The Initial System Loader (ISL) loads the HP-UX kernel into memory, providing a user interface to select the boot device and kernel options.
• Kernel Initialization: The kernel initializes core system components, including memory and process management, and device drivers.
• Init Process: The kernel starts the init process, which reads the /etc/inittab file to determine the system’s run level and necessary scripts.
• Run Level Scripts: The init process executes scripts in the /sbin/init.d directory to start system services and daemons.
• Login Prompt: The system displays the login prompt, allowing users to log in.

2. Write a shell script to monitor disk usage and send an alert if it exceeds 80%.

To monitor disk usage and send an alert if it exceeds 80%, use a shell script with the df command to check disk space and mail or echo for alerts:

#!/bin/sh

THRESHOLD=80

df -H | grep -vE '^Filesystem|tmpfs|cdrom' | awk '{ print $5 " " $1 }' | while read output;
do
  usage=$(echo $output | awk '{ print $1}' | sed 's/%//g')
  partition=$(echo $output | awk '{ print $2 }')
  if [ $usage -ge $THRESHOLD ]; then
    echo "Warning: Disk usage on $partition has reached $usage%" | mail -s "Disk Usage Alert" [email protected]
  fi
done

3. How do you configure network interfaces?

Configuring network interfaces on HP-UX involves using command-line utilities and editing configuration files:

• The ifconfig command configures network interfaces, such as setting IP addresses and netmasks.
• The /etc/rc.config.d/netconf file contains network configuration settings applied at startup.
• The netstat command displays network interface statistics.

Example:

# Configure the IP address and netmask for interface lan0
ifconfig lan0 192.168.1.10 netmask 255.255.255.0 up

# Add a default gateway
route add default 192.168.1.1

# Verify the configuration
netstat -in

4. Write a command to find all files modified in the last 7 days.

To find all files modified in the last 7 days, use the find command with the -mtime option:

find /path/to/directory -type f -mtime -7

Explanation:

• /path/to/directory: The directory to search.
• -type f: Ensures only files are considered.
• -mtime -7: Finds files modified in the last 7 days.

5. Describe how Logical Volume Manager (LVM) works and its benefits.

LVM in HP-UX provides a flexible method for allocating space on storage devices. It abstracts physical storage into logical volumes, which can be resized and managed easily.

LVM involves three main components:

• Physical Volumes (PVs): Actual physical storage devices.
• Volume Groups (VGs): Pools of storage created by combining multiple physical volumes.
• Logical Volumes (LVs): Virtual partitions created from volume groups.

Benefits of LVM include:

• Flexibility: Logical volumes can be resized dynamically.
• Ease of Management: Adding or removing storage devices can be done without downtime.
• Snapshots: LVM allows for the creation of snapshots for backups and data recovery.
• Striping and Mirroring: LVM supports striping and mirroring for improved performance and redundancy.

6. Write a script to automate the backup of a directory to another location.

To automate the backup of a directory, use a shell script:

#!/bin/sh

# Define source and destination directories
SOURCE_DIR="/path/to/source_directory"
DEST_DIR="/path/to/destination_directory"

# Create a timestamp
TIMESTAMP=$(date +"%Y%m%d%H%M%S")

# Create a backup directory with the timestamp
BACKUP_DIR="${DEST_DIR}/backup_${TIMESTAMP}"
mkdir -p "$BACKUP_DIR"

# Copy the contents of the source directory to the backup directory
cp -r "$SOURCE_DIR"/* "$BACKUP_DIR"

# Print a message indicating the backup is complete
echo "Backup of $SOURCE_DIR completed successfully to $BACKUP_DIR"

7. How do you check and repair filesystem errors?

To check and repair filesystem errors, use the fsck command:

• Unmount the filesystem using umount.

umount /dev/vg00/lvol1

• Run fsck with the device name to check and repair the filesystem.

fsck -y /dev/vg00/lvol1

• Remount the filesystem using mount.

mount /dev/vg00/lvol1 /mountpoint

8. Write a script to parse a log file and extract lines containing a specific keyword.

To parse a log file and extract lines containing a specific keyword, use a shell script:

#!/bin/sh

# Check if the correct number of arguments is provided
if [ "$#" -ne 2 ]; then
    echo "Usage: $0 <logfile> <keyword>"
    exit 1
fi

logfile=$1
keyword=$2

# Read the log file line by line
while IFS= read -r line
do
    # Check if the line contains the keyword
    echo "$line" | grep -q "$keyword" && echo "$line"
done < "$logfile"

9. Write a script to check the status of a service and restart it if it is not running.

To check the status of a service and restart it if it is not running, use a shell script:

#!/bin/sh

SERVICE_NAME="your_service_name"

if ps -ef | grep -v grep | grep $SERVICE_NAME > /dev/null
then
    echo "$SERVICE_NAME is running"
else
    echo "$SERVICE_NAME is not running, restarting..."
    /sbin/init.d/$SERVICE_NAME start
fi

10. Describe backup and recovery procedures.

Backup and recovery procedures in HP-UX ensure data integrity and availability:

Types of Backups:

• Full Backup: Captures all data.
• Incremental Backup: Captures only data that has changed since the last backup.
• Differential Backup: Captures all data that has changed since the last full backup.

Tools Used:

• fbackup/frecover: Native HP-UX tools for backups and recoveries.
• tar: Used for creating archive files.
• vxdump/vxrestore: Used for Veritas file systems.

Backup Procedure:

1. Identify the data to be backed up and choose the appropriate type of backup.
2. Schedule the backup during off-peak hours.
3. Use the chosen tool to perform the backup.
4. Verify the backup for data integrity.
5. Store the backup in a secure location.

Recovery Procedure:

1. Identify the data to be restored and locate the backup files.
2. Use the appropriate tool to restore the data.
3. Verify the restored data.
4. Update system configurations as needed.