Introduction to virtual private server (VPS): installation and running (1)

We areThe first article of the virtual private server (VPS)This article discusses why VPS is used. This article describes how to install and run VPS in detail.

You may have thought that you must have an account to experience VPS. No matter what kind of service you need, create an account first. Even if the credit card number has been verified, some host service providers still require another identity verification. This is clearly to prevent spam senders, phishing attackers, and hackers from using a stolen credit card that has not been reported to the owner or discovered.

For example, Rackspace indicates that it will contact you within 15 minutes after the account is created to verify your identity. However, when I create two accounts, the other party does not contact me.

After the account is created, you need to set the instance size. Most host service providers provide a standard setting menu for you to choose from: several services provide you with more options as you would like to order. Due to restrictions on how to set up virtual host servers, adding more content or hard disk storage space is often subject to a seemingly high cost. This is because the change may make it impossible for the service provider to provide complete additional servers on the same machine.

As part of instance configuration, you almost always have to choose which Linux release to use. Some VPS service providers also provide Windows Server options, which usually charge about 5% to 10% more than similar Linux platforms. Although each host supports different Linux distributions, most of them include CentOS, Debian, Fedora, red hat, and Ubuntu. ArchLinux, Slackware, and other releases appear in special host service providers. Some releases only appear in some data centers running by a company. In some cases, you can also choose between 32-bit and 64-bit virtual machines and operating systems. I have used the RedHat for many years and now I use CentOS instead. The change process is easy. Yes, I know that your Linux/BSD is much better than CentOS, but I can easily use this release to handle any task I want to handle .)

Standard release images are mounted to virtual machines, and your installed instances become persistent immediately. On the other hand, even if you close an instance on any service other than Amazon, you still have to pay hourly fees. The service provider will not continue to be charged only when the instance is deleted. Amazon does not charge fees for stopped instances started from persistent volumes. If you use some services, you can write the images of running or paused instances to the storage area. Therefore, you need to pay per GB per month to use the images.) You can restore the images from the storage area in the future. Amazon has always been an exception. It allows you to start from a non-continuous template image-you can customize the image, but the image will be deleted after it is disabled, you can also start from the persistent volume that retains all costs. You can also start from a regular non-persistent image and specify scripts that can be mounted to different persistent volumes .)

The instance includes an IP address obtained by the public contact, but you can add more addresses, you only need to pay the monthly fee. If you use older Apache versions that support SSL/TLS), you usually only need an additional IP address. You can also set a private IP address, which is generally free of charge. As described above, these private IP addresses allow communication between instances in a single data center run by the host service provider and are not charged separately. This is extremely useful if you need to send data back and forth frequently between your operating systems.

In all the situations I see, instances can be created when the firewall is enabled, and sometimes only remote access through SSH is allowed. Even SSH access may require more complex key-based authentication-Amazon does, instead of requiring only the user name and password. The task that requires the highest root user permission is to configure the firewall on the command line to enable the service that requires remote access. However, Amazon and other service providers have Web-based Firewall Configuration Wizard .)

Most Linux distributions are accompanied by related update services, such as the yum, Debian, and Ubuntu with Fedora and CentOS. Since some of my hardware servers have been running for several years and need a lot of customization to run normally, I rarely enjoy the convenience of automated updates. You should enjoy it.

The only problem with my release architecture is SSL/TLS and Apache. Apache's CentOS 5.5 release does not support server name indication SNI. This feature allows multiple SSL/TLS Web servers to share the same IP address. I had to roll up my sleeves and compile and Update openSSL and Apache. The problem is solved, but it does lose the pleasure of not compiling your own software. Currently, I am waiting for MySQL 5.5. This version already exists, but it is not part of the CentOS 5.5 release.

You can even install the upgraded kernel or simply replace the kernel. But it is dangerous to do so. The VPS host generally only provides limited support for the logic machines you run. Even so, it is only a standard release version provided by the service provider. If something goes wrong when you upgrade the kernel or convert the operating system, you may have to go back to the previously saved image.

Once you have a machine that fits your mind, there is almost always the option to save the image: This is sometimes linked to a separately charged or on-demand backup system. Saving images is a precise clone version of the server and is used by most hosts to create new instances. If you have reason to switch or establish redundancy mechanisms, images can usually be migrated between multiple data centers running in the same company.

What errors may occur after an instance is created and running? There will be many errors. However, properly running VPS hosts can largely offset potential problems.