Addendum: The hard drive is 250 GB capacity, a single NTFS partition.

OK, I figured it out today. The router creates a subfolder with a database file, with a .db extension. I just need to delete that file while connected to my PC, then when I reconnect it to the router, it will rebuild it correctly.

Now I have run into another problem, the database is limited in how many files can be indexed. As I kept adding music to the drive, it no longer got to the end of all the folders on the drive. Testing confirmed that the number of files on the drive has a cutoff point where indexing stops. So now I am faced with either removing some of my albums, or ripping entire albums to one MP3 file to reduce the total number of files. Not happy about this.

RoninWestMichigan wrote

OK, I figured it out today. The router creates a subfolder with a database file, with a .db extension. I just need to delete that file while connected to my PC, then when I reconnect it to the router, it will rebuild it correctly.

Yes, you are right. When pluging a usb disk and enable DLNA, router will run a full scan and generate a index file, which will be used for DLNA media file path.
But I also confuse why it don't generate a new one when you update files in the usb disk.

RoninWestMichigan wrote

Now I have run into another problem, the database is limited in how many files can be indexed. As I kept adding music to the drive, it no longer got to the end of all the folders on the drive. Testing confirmed that the number of files on the drive has a cutoff point where indexing stops. So now I am faced with either removing some of my albums, or ripping entire albums to one MP3 file to reduce the total number of files. Not happy about this.

How about separating the disk to several drive partition.

So you think that each partition would be able to support as many files as if I only have one partition?
I could certainly use a partitioning tool to create a 2nd partition and move some of the music to it.
Maybe it would be best to copy all its contents to a backup first, reformat it, restore files into the 2 partitions so I don't risk losing the contents.

I went back to read the manual and spotted this: "The router can share 32 volumes at most." I would assume that means partitions on hard drives;
also I could add a hub and as many as 3 more hard drives as a workaround, but I don't think I have any more spare 2.5" drives handy. I don't want to get into bulky 3.5" drives for this setup, ideally keep it as only the 1 drive if I can.

By the way. I figured in the short term, I would work around the limitation by ripping entire albums to one MP3. The software I have provides that option, and I have done that in a few cases so I can add more albums.

Ron

OK, I tried out the idea of a second partition, put one group of music files on the 2nd partition from a backup I made. I left that same group of files on the first partition, so that group of files is on both.
When I put the drive back on the router, it went to work rebuilding the database. It only made a database file on the first partition, when finished indexing the first partition, it went on to working on the files in the second partition, got part way through, got to the limit of the maximum files it can index, and stopped. It hit the limit because it was working with the duplicated set of files, without those, it would have indexed everything I had on it OK.
Therefore it does NOT help to create a second partition, you are limited to about 10,000 files on your hard disk either way.
I am suspecting that even if you were to use a USB hub and connect another hard drive, it would still make only one database file on the first partition of whatever it deems the first drive to be, and would still be limited to 10,000 files overall. Not going to test this idea. Maybe I will just set up a DLNA server on a PC and move my drive there, I bet that will not have the limitation in the number of files that can be hosted. I believe that the freeware Foobar can do the DLNA server hosting.

It would be great if someone from TP-Link tech support would address this, do they need to limit the amount of files due to the limited amount of RAM the router has to store the data in?
And I am curious about other brands of routers, do they have the same limitations, or maybe even fewer files supported?
I have read people posting that using a router is not a good way to run a home media server, and this may be a big part of why they feel that way.
I suppose it would work alright for videos, certainly not good for photos or for large music collections.

Ron

Sorry for my useless suggestion...
It seems there is a index No. limitation, other router also have, maybe different size.