The key differences between CentOS and Ubuntu are: origin (CentOS originates from Red Hat, for enterprises; Ubuntu originates from Debian, for individuals), package management (CentOS uses yum, focusing on stability; Ubuntu uses apt, for high update frequency), support cycle (CentOS provides 10 years of support, Ubuntu provides 5 years of LTS support), community support (CentOS focuses on stability, Ubuntu provides a wide range of tutorials and documents), uses (CentOS is biased towards servers, Ubuntu is suitable for servers and desktops), other differences include installation simplicity (CentOS is thin)

The CentOS shutdown command is shutdown, and the syntax is shutdown [Options] Time [Information]. Options include: -h Stop the system immediately; -P Turn off the power after shutdown; -r restart; -t Waiting time. Times can be specified as immediate (now), minutes ( minutes), or a specific time (hh:mm). Added information can be displayed in system messages.

Software preparation I am using a virtual machine with CentOS-6.6, with the host name repo. Refer to the steps to install a Linux virtual machine in Windows, I installed JDK in that virtual machine, refer to the guide to installing JDK in Linux. In addition, the virtual machine is configured with a key-free login itself, and the settings for configuring key-free login between each virtual machine are referenced. The download address of Hadoop installation package is: https://mirrors.aliyun.com/apache/hadoop/common/. I am using hadoop 2.6.5 version. Upload the Hadoop installation package to the server and unzip [root@repo~]#tarzxv

Steps to configure IP address in CentOS: View the current network configuration: ip addr Edit the network configuration file: sudo vi /etc/sysconfig/network-scripts/ifcfg-eth0 Change IP address: Edit IPADDR= Line changes the subnet mask and gateway (optional): Edit NETMASK= and GATEWAY= Lines Restart the network service: sudo systemctl restart network verification IP address: ip addr

CentOS will be shut down in 2024 because its upstream distribution, RHEL 8, has been shut down. This shutdown will affect the CentOS 8 system, preventing it from continuing to receive updates. Users should plan for migration, and recommended options include CentOS Stream, AlmaLinux, and Rocky Linux to keep the system safe and stable.

1. The Origin of .NETCore When talking about .NETCore, we must not mention its predecessor .NET. Java was in the limelight at that time, and Microsoft also favored Java. The Java virtual machine on the Windows platform was developed by Microsoft based on JVM standards. It is said to be the best performance Java virtual machine at that time. However, Microsoft has its own little abacus, trying to bundle Java with the Windows platform and add some Windows-specific features. Sun's dissatisfaction with this led to a breakdown of the relationship between the two parties, and Microsoft then launched .NET. .NET has borrowed many features of Java since its inception and gradually surpassed Java in language features and form development. Java in version 1.6

Common problems and solutions for Hadoop Distributed File System (HDFS) configuration under CentOS When building a HadoopHDFS cluster on CentOS, some common misconfigurations may lead to performance degradation, data loss and even the cluster cannot start. This article summarizes these common problems and their solutions to help you avoid these pitfalls and ensure the stability and efficient operation of your HDFS cluster. Rack-aware configuration error: Problem: Rack-aware information is not configured correctly, resulting in uneven distribution of data block replicas and increasing network load. Solution: Double check the rack-aware configuration in the hdfs-site.xml file and use hdfsdfsadmin-printTopo

Improve HDFS performance on CentOS: A comprehensive optimization guide to optimize HDFS (Hadoop distributed file system) on CentOS requires comprehensive consideration of hardware, system configuration and network settings. This article provides a series of optimization strategies to help you improve HDFS performance. 1. Hardware upgrade and selection resource expansion: Increase the CPU, memory and storage capacity of the server as much as possible. High-performance hardware: adopts high-performance network cards and switches to improve network throughput. 2. System configuration fine-tuning kernel parameter adjustment: Modify /etc/sysctl.conf file to optimize kernel parameters such as TCP connection number, file handle number and memory management. For example, adjust TCP connection status and buffer size