We're migrating our server to OEL 7, and wanted to check if version 4.2 will run on it.
There is no real reason, for not working on it.
But if you refer to Alfresco Enterprise 4.2 (Content Services is the name adopted in 5.2 version) please check the supported stack for 4.2:
Supported Platforms | Alfresco
If you are using Community version, this stack gives you an idea of the more tested components near this version (when applies - for example, OS, postgres/mysql database or Libreoffice version).
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