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studying. There maybe a lot wrong going on.
목차
Interview Questions
1. 직무 이해도
What is the Role of Data Center Technician?
Data Center Technician is responsible for the maintenace, troubleshooting, and repair of hardware and infrastructure in a data center. They ensure the uninterrupted operation of servers and associated equipment.
Can you provide an example of a preventive maintenacne task in a deta center?
Regularly cleaning server components to prevent dust buildup and checking for loose cables are essential preventive maintenance tasks. They help in preventing potential hardware issues.
2. 트러블 슈팅
How do you handle hardware failures in a data center?
I follow these steps:
- Identify the failed componet using monitoring tools.
- Replace the faulty hardware with a spare.
- Perform necessary tests to ensure proper functioning.
- Update records and documentation.
What is the purpose of a remote hands service in a data center?
Remote hands service allows for troubleshooting, maintenace, and physical tasks to be performed by off-site technicians. This is crucial for efficiency and quick response to issues.
How do you conduct a risk assessment in a data center environment?
I identify potential risk such as power failures, network issues, and hardware failures. Then, I evaluate their impact and likelihood, and implement measures to mitigate or minimize them.
How do you handle a situation where a critical server fails to boot?
I first check for loose connections of faulty components. If needed, I would boot from a recovery disk or perform troubleshooting steps specific to the server’s hardware.
How do you handle a situation where a data center is at risk of flooding?
I ensure critical equipment is elevated, implement waterproofing measures, and establish protocols for shutting down non-essential systems. Additionally, I monior weater alerts an have a disaster recovery plan in place.
How do you prioritize tasks when multiple critical issues aires simultaneously?
I assess the impact and urgency of each issue. Critical systems with the highest impact and urgency are addressed first, followed by less critical tasks.
3. 하드웨어/네트워크
Explain the importance of redundancy in a data center.
Redundancy ensures that critical systems have backups in case of failures. This includes redundant power supplies, network connections, and cooling systems, minimizing downtime and ensuring continuos operation.
Explain the purpose of a DCA(Data Center Interconnect) in a multi-data center environment.
A DCI links multiple data centers, allowing them to operate as a single unit. It enables seamless data replication, load balancing, and disaster recovery across geographically distributed facilities.
Explain the role of a UPS(Uninterruptible Power Supply) in a data center.
A UPS provides temporary power during electrical outages. It ensures a smooth transition to backup generators, preventing any interruption to critical systems.
Explain the purpose of a RPS(Redundant Power Supply) in a data center.
A RPS ensures uninterrupted power to critical equipment in case of a primary power source failure. It adds an extra layer of reliability and minimizes downtime.
Expalin the concept of Hot and Cold Aisles in a data center.
In a hot aisle/cold aisle layout, servers are arranged so that cold air is directed into the front of the servers(cold aisle) and hot air is expelled out the back(hot aisle). This improves cooling efficiency.
Explain the role of RAID(Redundant Array of Independent Disks)
RAID combines multiple hard drives to improve performance, reliability, and redundancy. Different RAID levels offer varying degrees of data protection and speed.
Explain the purpose of PDU(Power Distribution Unit) in a data center.
A PDU distributes electrical power to servers and networking equipment within a rack. It provides multiple outlets, allowing for efficient power management and load balancing.
Explain the role of a KVM Switch in a data center.
A KVM(Keyboard, Video, Mouse) switch allows technicians to manage multiple servers from a single console. It simplifies troubleshooting and maintenance tasks.
Explain the pupose of A Rack Unit(U) measurement in a data center.
A Rack unit is a standard measure of vertical space in a rack. It is used to determine the height of equipment, allowing for efficient utilization of rack space.
Explain the role of VLAN(Virtual Local Area Network) in a data center.
A VLAN logically divides the physical network into seperate virtual networks. It enchances security, improves performance, and simplifies network management in a data center environment.
Explain the purpose of a CDN(Content Delivery Network) in a data center.
A CDN distributes content across multiple servers geographically closer to end-users. This reduces latency and improves the delivery speed of web content, enhancing user experience.
Explain the role of a Load Balancer in a data center.
A Load Balancer distributes incoming network traffic across multiple servers, ensuring no single server becomes overloaded. This enchances the performance, availability, and reliability of applications.
Explain the purpose of a SAN(Storage Area Network) in a data center.
A SAN provides high-speed, block-level access to storage resources, allowing servers to access shared storage devices. It is used for critical applications and data requiring high availavility.
Explain the purpose of a Network Switch in a data center.
A Network switch connects multiple devices within a network, allowing them to communicate efficiently. It operates at the data link layer of the OSI model, improving network performance.
Explain the purpose of an ILO(Integrated Lights-Out) in a data center.
ILO is a remote management interface that allows administrators to monitor and manage servers even if the operating system is not running. It provides out-of-band management capabilities.
Explain the purpose of a Blade Server in a data center.
A blade server is a compact, modular server that shares resources with other blade servers. It reduces the physical footprint, simplifies management, and enhances scalabiltiy in a data center.
Explain the purpose of a console server in a data center.
A console server provides out-of-band access to network devices and servers. It allows administartors to manage and troubleshoot equipment even if the network is down.
Explain the purpose of a storage array in data center.
A storage array is a centralized storage system that provides high-capacity storage for servers. It allows for scalable and shared storage resources, enhancing data management capabilties.
Explain the purpose of a NIC(Network Interface Card) in a data center.
A NIC is a hardware component that connects a server to a network. It enables communication between the server and other devices, allowing data transfer over the network.
Explain the purpose of a firewall in a data center.
A firewall is a security device that filters incoming and outgoing network traffic based on an applied rule set. It acts as a barrier between a trusted network and untrusted networks(like the internet), preventing unauthorized access and potential threats.
4. 리눅스 Sheell script
Provide an Example of a code snippet for automating server monitoring.
#!/bin/bash
server="example.com"
status=$(ping -c 1 $server | grep "1 packets transmitted, 1 received")
if [ -z "$status" ]; then
echo "Server $server is down."
else
echo "Server $server is up."
fi
This script checks if a sever is reachable.
Provide an Example of a code snippet for automating server Backups.
#!/bin/bash
source_dir="/var/www"
backup_dir="/backup"
tar -zcvf $backup_dir/backup_$(date +\%Y\%m\%d).tar.gz $source_dir
This script creates a compressed backup of a directory.
Provide an Example of a code snippet for automating server backup scheduling.
#!/bin/bash
backup_dir="/backup"
rsync -av --delete /data $backup_dir
Provide an Example of a code snippet for automating server database backups.
#!/bin/bash
database="mydatabase"
backup_directory="/backup"
mysqldump -u username -p password $database > "$backup_directory/$database-$(date +%Y%m%d).sql"
This script creates a backup of a MySQL database.
Provide an Example of a code snippet for monitoring server disk space.
#!/bin/bash
threshold=90
current_usage=$(df -h / | awk 'NR==2{print $(NF-1)}' | tr -d '%')
if [ "$current_usage" -ge "$threshold" ]; then
echo "Disk space is running low."
else
echo "Disk space is within acceptable limits."
fi
This script checks if disk space usage is above a specific threshold.
Provide an Example of a code snippet for automating server log monitoring.
#!/bin/bash
log_file="/var/log/syslog"
error_pattern="ERROR"
if grep -q "$error_pattern" $log_file; then
echo "Errors found in the log file."
else
echo "No errors found."
fi
This script checks for errors in a log file.
Provide an Example of a code sinppet for automating server performance monitoring.
#!/bin/bash
cpu_threshold=90
cpu_usage=$(top -bn1 | grep "Cpu(s)" | awk '{print $2}' | awk -F. '{print $1}')
if [ "$cpu_usage" -ge "$cpu_threshold" ]; then
echo "High CPU usage detected."
else
echo "CPU usage within acceptable limits."
fi
The script checks if CPU usage exceeds a specified threshold.
Provide an Example of a code snippet for automating server security check.
#!/bin/bash
open_ports=$(netstat -tuln | grep LISTEN | awk '{print $4}' | awk -F: '{print $NF}')
if [ -z "$open_ports" ]; then
echo "No open ports found."
else
echo "Open ports: $open_ports"
fi
The script checks for open ports on a server.
Provide an Example of a code snippet for automating server backup verification.
#!/bin/bash
backup_dir="/backup"
if [ -d "$backup_dir" ] && [ "$(ls -A $backup_dir)" ]; then
echo "Backup directory is not empty."
else
echo "Backup directory is empty or does not exist."
fi
This script checks if a backup directory is populated.
Provide an Example fo a code snippet for automating server log rotation.
#!/bin/bash
log_file="/var/log/application.log"
max_size=10M
backup_count=5
if [ -f "$log_file" ]; then
log_size=$(du -m "$log_file" | awk '{print $1}')
if [ "$log_size" -ge "$max_size" ]; then
mv "$log_file" "$log_file.1"
touch "$log_file"
gzip "$log_file.1"
fi
fi
This script rotates logs based on size.
Provides an Example of a code snippet for automating server certificate expiration checks.
#!/bin/bash
cert_file="/etc/ssl/cert.pem"
expiry_date=$(date -d "$(openssl x509 -noout -in $cert_file -dates | grep notAfter | cut -d= -f2)" +%s)
current_date=$(date +%s)
days_until_expiry=$(( ($expiry_date - $current_date) / (60*60*24) ))
if [ "$days_until_expiry" -lt 30 ]; then
echo "Certificate expires in less than 30 days."
else
echo "Certificate expiration is within acceptable limits."
fi
Provide an Example of a code snippet for automating server user account management.
#!/bin/bash
username="newuser"
password="password123"
useradd -m -p $(openssl passwd -1 $password) $username
# or
echo -e "$password\n$password" | passwd $username
This script creates a new user account with a specified password.
Provide an Example of a code snippet for automating server service monitoring.
#!/bin/bash
service="apache2"
if systemctl is-active --quiet $service; then
echo "$service is running."
else
echo "$service is not running."
fi
This script checks if a service is running.
Provide an Example of a code snippet for automating server software updates.
#!/bin/bash
apt update
apt upgrade -y
This script updates the software packages on a Debian-based system.
Provide an Example of a code snippet for automating server resource utilization monitoring.
#!/bin/bash
memory_threshold=90
memory_usage=$(free | grep Mem | awk '{print $3/$2 * 100}')
if [ "$memory_usage" -ge "$memory_threshold" ]; then
echo "High memory usage detected."
else
echo "Memory usage within acceptable limits."
fi
This script checks if memory usage exceeds a specified threshold.
Provide an Example of a code snippet for automating server log monitoring for specific keywords.
#!/bin/bash
log_file="/var/log/application.log"
keyword="ERROR"
if grep -q "$keyword" "$log_file"; then
echo "Error found in $log_file"
else
echo "No errors found."
fi
This script checks for a specifc keyword in a log file.
Provide an Example of a code snippet for automating SSL certificate renewal.
#!/bin/bash
cert_file="/etc/ssl/cert.pem"
days_until_expiry=$(openssl x509 -noout -in $cert_file -dates | grep notAfter | cut -d= -f2)
if ! openssl x509 -checkend $((60*60*24*30)) -noout -in $cert_file; then
echo "Certificate needs to be renewed."
else
echo "Certificate is valid."
fi
#!/bin/bash
certbot renew
This script checks if an SSL certifiacte needs renewal.
Provide an Example of a code snippet for automating server SSL certificate installation.
#!/bin/bash
cert_file="server.crt"
key_file="server.key"
cp $cert_file /etc/ssl/certs/
cp $key_file /etc/ssl/private/
This script copeis SSL certificate and key files to their respective directories.
Provide an Example of a code snippet for automating server firewall rule management.
#!/bin/bash
port=80
iptables -A INPUT -p tcp --dport $port -j ACCEPT
Provide an Example of a code snippet for automating server vulnerability scanning.
#!/bin/bash
nmap -p 1-65535 -T4 -A -v target_host
This script uses nmap to perform a through vulnerability scan on the target host.
Provide an Example of a code snippet for automating server container deployment.
#!/bin/bash
docker run -d --name my_container my_image
This script deploys a container using a specified Docker image.
Dump
아 이 이상 정리할 수 없어….귀찮아~
- Do you know what racket stack means?
- Have you used an Ethernet test?
- 제발 질문 좀 해
- Can you tell me what a normal day is like
- What is the difficulties the team is running into the moment?
- How can i succeed in this job ?? 아니 진짜??…. 이해할 수 없는 외국계기업