On 01/09/2021 11:24, Mark Woolfson wrote: Hi Mark, > Please can you give me an idea of the migration complexity of moving the > applications from 6.4/6.6 to 7.4 or any variant of 7. This is a very vague question. It's like asking "I have an old car. Can you please tell me if I can drive it on the new motorway?" Folk can't really help you this way. You need to provide more specific information, such as what language these apps are written in. Are they written in C which is compiled? Has it been statically compiled, or dynamically? What libraries does it link against? Perhaps the application is in Java, Python, Perl or Ruby. Then it's easier, but again, there may be some gotchas. Do you have the source code of the applications? If you do, then it's easier to make them work in case modifications are needed. If you don't have the source, then things become trickier. If the applications won't run under CentOS 7, and you can't modify them, then you might want to consider running them in CentOS 6 containers on a CentOS 7 or 8 host. But give details, man! Without details, it's all guesswork. Regards, Anand