NAS connection issue

Make sure that all these volumes are really unmounted - failure to do this will result in BIG PROBLEMS!!!!

Then, in a terminal window try this:

cd /Volumes
ls -la

You will see multiple occurrences of the DriveName item -- these are still hanging around because the drive was not properly unmounted before, and on subsequent requests to mount DriveName the system automatically has created DriveName-1, etc

So, if the real DriveName is now unmounted (be absolutely certain of this) by running the command:

df -kt

Then if you don't see any DriveName or DriveName-1 or other variations do this:

cd /Volumes
sudo rm -r DriveName*

and you will be prompted for the admin password - supply it and all the bogus folders will be removed. You can then use DiskUtility or other tools to now mount the real DriveName volume. In the future, make sure there are no bogus DriveName folders in the /Volumes folder before trying to mount the real DriveName volume.

Just to make sure -- do not run that last command by accident with a real DriveName or DriveName-1 or any other variation without being certain it is no longer mounted. If you are mistaken, you have just removed all the files in your NAS drive, which is probably not a good idea ;-)

As to why the OS keeps around these old mount points, I can't really say. Just something to be aware of when remounting that DriveName volume and clean up before doing so if needed.

Good luck...

I believe the problem is when they get improperly dismounted -- a proper unmount will remove the entries in the /Volumes folder. The first time this happens, the /Volumes/DriveName remains and the next mount gets confused I guess because it sees the /Volumes/DriveName still exists, so it creates a new /Volumes/DriveName-1, and so on and on it goes.

A reboot will also "fix" the problem, right?

I think the underlying reason has to do with when macOS goes to sleep -- the USB interfaces loose power and the drive does some sort of disconnect that invalidates the mount point and when the system wakes up again it tries to auto mount the same drives that were there when it went to sleep, but that is just my personal theory and have no knowledge or facts to base this on. More of a hunch really. Do you put the system sleep or do a full shutdown?

I think the Synology folks would be the best to consult on how they recommend doing an auto mount of their NAS box -- network mounted filesystems don't seem to get auto mounted the way directly connected USB or Firewire or Thunderbolt external drives do. Take a look at https://www.imore.com/how-automatically-mount-network-drives-macos (they show a way to add an item to your login items so that the NAS drive gets mounted whenever you login).

Anyway, glad to have helped...and

Good luck...