External hard drive indexing

Start by making sure the drive is not excluded from being indexed by opening System Preferences > Spotlight > Privacy.

The subsequent list you should see on this page is a list of all locations that Spotlight is prohibited from searching. If your drive is listed, select it and remove it from the list.

If your drive was listed and you removed it from this list then your problem will be resolved the next time Spotlight re-indexes your files.

You can force Spotlight to re-index your files and if your drive was not on the previous list then this would be the next step in attempting to resolve the issue. Open Terminal.app and issue the following command to clear out Any existing index and have Spotlight do a completely fresh re-index of your entire system.

    
    sudo mdutil -Ea
    mdutil -ai off
    mdutil -ai on

Alternatively if you want to just re-index the drive in question you can have Spotlight re-index any specific location by modifying the command slightly like so

sudo mdutil -E /Volumes/YourDriveName

If the issue is still not resolved open Disk Utility and run First Aid on the drive to ensure there are no errors. Also be sure that if you disconnect the drive you are unmounting it properly before physically disconnecting it and you are not disconnecting it while the index is in progress.

Control (right) - click on the drives icon on the Desktop and select "Get Info" from the contextual menu. The Info pane will have the format info here:

What is it? Most drives come formatted for PCs and not Macs.

If the drive is not visible in Finder or Disk Utility the problem is likely to do with the way in which it is connected to the computer. The cable you are using or the port you are connected to may not be delivering enough power to the drive for it to fully initialize.

Trying using a different cable and different ports to see if the issue persists. If it doesn’t then you can determine which port or cable is not functioning properly.

Alternatively, if the drive does not show in Finder but in Disk Utility it is listed but grayed out then you simply have the drive formatted incorrectly and can resolve the issue by reformatting the drive. To recover the data before reformatting you can attempt to connect to it using a Windows OS to offload the data.

Duh! Telepathy?

Tunnel vision makes one miss the obvious. 🤭

Have you tried a different cable or port?

Have you tried: How to reset the SMC of your Mac - Apple Support

What is the manufacture and model of the drive that's giving you problems?

Have you tried Disk Utility like DCondrey suggested? Any error indications?

How is the drive formatted?

djaytch wrote:

thinking of switching to Brandy!

Make that a double!

Do you have access to another Mac where you could connect it and see if it shows up as it should and search it accordingly?