How to overcome common problems of migration from Unix to Linux

After the initial test, you have already planned to migrate from Unix to Linux. What are the main problems you should pay attention to now? What problems or errors do Unix often encounter during migration to Linux? Who should you ask for help? A good plan allows you to avoid these problems.

Identify possible hardware challenges

When considering the migration process, we should pay attention to the platform dependency, especially the migration from the server guard to the X86 platform. In this case, Endianess can be used.

Endianess refers to the memory sorting used to display data. It specifies how data elements and bytes are stored in memory. The problem you may encounter is that Endian is rarely used in x86 computer systems, but it is used in a large number in the RISC system. If you want to migrate data from a Windows server to x86, and vice versa, You need to modify the migration code. In the evaluation phase, you should be aware of these problems.

Some manufacturers have come up with some creative solutions to solve these problems. For example, IBM developed PowerVM Lx86, a part of a medium-sized virtualization engine. It uses special software to automatically convert commands into voltage signals without compilation on the local machine.

Before Linux runs on the IBM Power platform, Linux must run locally and re-compile. Of course, this is no longer a problem. As a part of PowerVM Lx86, the converter can easily switch x86 Linux commands to voltage Liunx commands in three steps: decoding, optimization, and production code. This is very suitable for Web applications, because there is a lot of repetitive work, because these frequently used code is already in the memory, so there is no need to re-convert.

Another aspect to consider is the kernel extension and Device Driver required by the application. Finding appropriate kernel extensions and device drivers for applications is not easy, in part because most kernel APIs do not comply with standards. The number of API commands and parameters and the process of calling to kernel extension are different on the new platform.

Another concern is the applications that require kernel extensions and device drivers. These are not easy candidate support because most kernel APIs do not follow any strict standards. The number of parameters called by the API and the number of parameters loaded to the new platform with different functions during kernel expansion.

Evaluate the applicability and validity of applications for Linux

Most commercial and network applications can run on Linux. However, validity is another thing.

Although almost all manufacturers have moved their Unix applications to Linux today, the key is that before considering migration, how to ensure that the existing application can support such migration well. Otherwise, you will have to go into the trouble of migrating these applications on your own. For internal application development, you need a powerful development team to help complete application migration.

Consult with colleagues who have such experience. Learn how your application will migrate to Linux. Verify the current running status of these applications. Don't worry. Please request help from your manufacturer. Both Red Hat and SUSE provide services to help you complete the migration.

Deployment problems and errors

What errors or problems may you encounter when performing migration? First, proper testing is necessary. During the migration process, everything may go wrong. Therefore, you should build a test and experiment environment before creating the environment to discover and experience problems.

A few years ago, my team seemed to have successfully completed an important migration, but soon I began to receive a call saying that the wage management system was not working properly. This was a little unexpected. We previously conducted system unit testing, user testing, and UAT testing. It turns out that the problem is not about migration, but because some PC clients cannot be well compatible with the old Oracle clients.

Another problem is the Unix shell script. Some people may assume that Unix shell scripts can run well on Linux platforms. Unfortunately, this assumption is not true.

Any Unix script related to the application needs to be carefully tested. The standard Linux Shell uses the Bash shell, which is built on the original Unix Bourne shell. However, in our example, Unix uses the Korn shell. Therefore, some functions cannot work correctly. Therefore, it is necessary to assume that your shell script may not work properly in the new platform. Test every shell script you need.

Obtain technical support

Technical support depends on the size of your IT department and the experience of its employees. Do you have any omnipotent and experienced Linux administrators? Or maybe they are Unix administrators, but are they ready to accept Linux?

The degree of technical support depends on the type of environment you are using. Are you running systems that can cause tens of thousands of dollars in losses to your company due to every minute's failures, such as CRM or payroll systems?

Technical support from manufacturers is also very important. Both Red Hat and Novell provide 24/7 technical support. Some Unix hardware manufacturers, such as IBM, also provide their own Linux technical support.

If possible, obtain technical support from your hardware provider. In addition, this will not have any adverse impact on the technical support you obtain from the operating system provider. Finally, you need to carefully consider the economic impact of system downtime in your organization and the experience and capabilities of your employees.