Building Search Index

I have never seen the building search index thing. Not sure wat that is. Normally by far the fastest way to import images is to select copy (if you are importing from a memory card) and to use embedded previews in the preview section and to NOT create smart previews. This will just copy the images to your storage location and extract the jpeg previews from the raw files which is way faster than generating your own previews. Lightroom generated previews will now only get generated if you actually edit the image. Indeed make sure you don't have face detection turned on. You can either pause it from the nameplate or turn it off in catalog settings->metadata

First did you Move the Actual Catalog file to an External drive? Or did you move just your images?

Clcik the Pause button on the face and address lookups.

I persoanlly have never seen that entry for Search Indexing.

Als you have Selected Copy As DNG in the import dialog and that is why LrC is converting your images to DNG files. You need to Review all the options in the import dialog window before you click the Import button. And Or Create an Import Preset that sets all the option you want for a Normal/Standard import that you do and make sure it is selected and or the options you want are selected every time before you click that Import button.

I am curently doing an import of JPG images that were already on my drive so I used the Add option in the import wiindow and I do not get any Building Search Indexing. But then I have the Win 10 Search indexing system turned off on my system. Not sure if it is LrC that is doing that or the OS and LrC is just Reflecting that operation. It could also be the Face and Address system that is causing that which I have Paused.

Also see:

https://community.adobe.com/t5/lightroom-classic/turning-off-quot-building-search-index-quot-upon-import/td-p/9163741?page=1

You seem to be suggesting that Lightroom is automatically converting your images to DNG. That is not the case. Converting to DNG is one of the options at the top of the import dialog, along with Copy, Add (If the images are already on your hard drive) and Move (again, if the images are already on your hard drive). But these are options that you need to take care of when setting up your import choices. You are in control, so take it and run with it.

You can turn off Face detection and address lookup (click on the nameplate at the top left). You can also turn off the sync with Lightroom mobile, depending on your version of Lightroom Classic, so in version 9.4 this is done via the cloud icon at top right.

If that's not it: What do you see? Show us a screen capture.

Also, what specifically is being converted to DNG? Where do you see this is happening? What do you see? Please be specific and detailed. Show us a screen capture.