Easiest way to migrate web app to a new farm

Question

Our current farm is corrupt because all of the service applications have configuration issues. Our physical layout is 2 WFE, 2 app, and 2 db servers in a sql cluster. Is it possible to move the SharePoint - 80 web app from the old farm to the new farm or would that defeat the purpose of creating fresh service applications in the new farm? My concern is that I am reusing the same VMs for the new farm and I've never had to migrate before.

Thanks,

Answer 1

Yes, you can migrate the existing Web app to new farm. You need to have backup of the content database...here are the steps

• build new farm
• create n configuration new service apps
• create n configure new Web app (authentication, aam, any customizations)
• now take the backup of content database from old farm (sql server)
• restore it to new farm's sql server.
• detach the current content db from new we app
• attached the restored db to Web app
• test it

Update:

As you mentioned your scenario in comment, then following will be steps.

• Remove App2 from current farm.
• Create and Configure the new farm on the App2 using the same sql server but new Config DB.( i would higly recommend that uninstall the sharepoint completey and reinstall it on new farm to avoid any leftover from previous farm, and also make sure you should build the new farm as same version level or higher.)
• Add more servers to this farm same way. You can do this at the end as well.
• Create and Configure the Services apps on the new farm.
• Create and Configure the new Web app.
• deploy solutions(if any), custom changes to 14hive, web.config changes, AAM settings, IISbinding ( all if apply).
• Now detach the content DB from new Web app and attach the old Content DB from SQL cluster. Note: You dont need to create a new SQL cluster, just make sure Content DB also detached from the old Farm before attaching to new farm.
• test it.