Commands to properly close Linux systems include shutdown, halt, poweroff and reboot. Among them, shutdown is the most recommended, which can arrange shutdown time and send notifications; halt directly stops the system operation; poweroff cuts off the power supply based on halt; reboot is used for restart. To safely arrange a timed shutdown, you can use sudoshutdown-h 10 to indicate shutdown after 10 minutes, use sudoshutdown-c to cancel the timing, and add prompt information such as sudoshutdown-h23:00 "The system will be shut down at 11 o'clock tonight." Under the graphical interface, you can select Shutdown through the menu in the upper right corner.

The steps to add a new hard disk to the Linux system are as follows: 1. Confirm that the hard disk is recognized and use lsblk or fdisk-l to check; 2. Use fdisk or parted partitions, such as fdisk/dev/sdb and create and save; 3. Format the partition to a file system, such as mkfs.ext4/dev/sdb1; 4. Use the mount command for temporary mounts, such as mount/dev/sdb1/mnt/data; 5. Modify /etc/fstab to achieve automatic mount on the computer, and test the mount first to ensure correctness. Be sure to confirm data security before operation to avoid hardware connection problems.

Problems with device drivers will cause the hardware to not be used normally, such as peripherals not responding, system prompts "unknown device" or game stuttering. The solution is as follows: 1. Check the warning icon in the device manager. The yellow exclamation mark represents the driver outdated or compatibility problem. The red cross indicates that the hardware is disabled or the connection is poor. The question mark or "Otherdevices" means that the system has not found a suitable driver; 2. Right-click the device and select "Update Driver", try automatic search first, and manually download and install; 3. Uninstall the device and check delete driver software, and after restarting, let the system re-identify, or manually specify the driver path to install; 4. Use the driver identification tool to assist in finding models, but avoid downloading drivers from unknown sources; 5. Check Windows updates to obtain

In Linux systems, network interface information can be viewed through ip, ifconfig and nmcli commands. 1. Use iplinkshow to list all network interfaces, add up parameters to display only active interfaces, and use ipaddr or ipad to view IP allocation status; 2. Use ifconfig-a to be suitable for old systems, and you can view all interfaces. Some new systems need to install net-tools package; 3. Use nmclidevicestatus to be suitable for systems managed by NetworkManager, which can view interface status and connection details, and supports filtering and query. Select the appropriate command according to the system environment to complete the network information viewing.

Managing AWSEC2 instances requires mastering life cycles, resource configuration and security settings. 1. When selecting an instance type, select C series for calculation-intensive tasks, and select M or R series for memory-sensitive applications, and start with small-scale testing; 2. Pay attention to security group rules, key pair storage and connection methods when starting the instance, and Linux uses SSH commands to connect; 3. Cost optimization can be achieved through reserved instances, Spot instances, automatic shutdown and budget warning. As long as you pay attention to the selection, configuration and maintenance, you can ensure stable and efficient operation of EC2.

When managing cron tasks, you need to pay attention to paths, environment variables and log processing. 1. Use absolute paths to avoid commands or scripts not being found due to different execution environments; 2. Explicitly declare environment variables, such as PATH and HOME, to ensure that the variables dependent on the script are available; 3. Redirect output to log files to facilitate troubleshooting; 4. Use crontab-e to edit tasks to ensure that the syntax is correct and takes effect automatically. Mastering these four key points can effectively avoid common problems.

The top command can view the Linux system resource usage in real time. 1. Enter top through the terminal to open the interface, and the top displays the system running status summary, including load, task number, CPU and memory usage; 2. The process list is sorted by CPU usage by default, which can identify highly occupant processes; 3. Shortcut keys such as P (CPU sort), M (memory sort), k (end process), r (adjust priority), and 1 (multi-core details) improve operation efficiency; 4. Use top-b-n1 to save output to a file; 5. Adding the -u parameter to filter specific user processes. Mastering these key points can quickly locate performance issues.

Running Ansibleplaybook requires first ensuring that the structure is correct and the environment is prepared. 1. Write a playbook file, including hosts, tasks, etc.; 2. Ensure that the target host is in the inventory and can be connected through SSH, and can be tested by ansibleping module; 3. Use the ansible-playbook command to run, and you can add -i to specify the inventory path; 4. You can use -v, --check, --limit, --tags and other parameters to debug or control execution; 5. Pay attention to common error points such as YAML indentation, module parameters, permissions and inventory content. Using --check and -v will help troubleshoot errors