1. You can move the folder in IMatch to its new disk. This automatically updates the database.
Or do it in a tool of your choice (while IMatch is not running!) and use relocate afterwards. See Off-line Folders and Files (https://www.photools.com/help/imatch/#offline-files.htm) in the IMatch Help System.
I'm not sure that I understand this...
Quoterather than copying/dragging & dropping each via Windows Explorer.
Have you created hundreds of new folders on the same level? Without a parent folder?
Note that you can select multiple folders in Windows Explorer and drag them to IMatch.
You can also Commands menu > Add new Folders... command to add multiple folders at once.
Do not add new folders while you are moving folders using an external software to another disk in the background. This may cause issues with Windows file system messages.
Just mirror your drive (or copy individual folders if you must). If disk #1 dies, either change the serial number of the new disk (there are tools for that) or use relocate in IMatch.
Note: Sometimes users make their life extra hard by managing dozens or even hundreds of folders on the root level of a disk.
It is always better to create something like c:\images or c:\data or c:\data\images and then create all folders below that root folder. This makes relocating, backup etc. much easier.