For safety purposes, I regularly sync the M: drive to a second drive, seen by Windows as D: labelled “mu-usb-bck-1”. Following the sync, both drives have an identical file structure, only the drive letters change. Drive D: is mounted only to perform the sync, and kept offline otherwise. Drive M: is always online.
Here is my problem. Just after mounting drive D: in preparation for the sync, I went to the Roon > Settings > Storage screen, and saw that Roon reports that my watched folders are now on drive D:, not on M: as expected (note: M: was still mounted):
I started to fear that this unexpected switch of drives may corrupt the Roon database. I rapidly unmounted the D: drive, and went again to the Roon > Settings > Storage screen, now to see that the drive is not ready:
My only option seemed to kill Roon, which I did. Upon restarting Roon, everything came back to a normal state (I hope!), with the watched folders correctly identified as residing inside the M: drive as usual.
This appears to indicate that Roon has trouble distinguishing on Windows file paths which only differ by their initial drive letter, perhaps because the drive letter is not stored in the Roon database. Could the situation reported above have resulted in a corrupt Roon database, for ex. if Roon would have decided to rescan the D: drive which was out-of-sync with the M: drive ? This is pretty scary!
If there is indeed a problem here, does this mean that I should always stop Roon before mounting the D: drive to perform the execute the sync ?
Windows is not the cleverest operating system, would it be a huge pain for you to swap your drives over, i.e. Make the actual drive the d drive and the backup one the m drive and test it out that way?
Do you suggest that assigning the “base” drive a letter lower in the alphabet than the one assigned to the drive used to sync it could solve the issue ? In that case, I would prefer to leave the base drive untouched and reassign the letter of the sync drive so that it sorts higher than that of the base drive.
To be clear: base drive stays at M:, and sync drive is reassigned to N: . Is this sensible ?
Unfortunately no luck! I reassigned the target sync drive to letter O: so that it sorts after the drive letter M: of the base drive. Simply plugging in the O: drive made Roon immediately switch the watched folders to O: ,as before. Unmounting the O: drive leaves me with a DriveNotReady indication. Stopping and restarting Roon corrects the situation.
Quite frankly, I never paid attention to that in the past. I did not run Roon quite often before arrival of v1.3. Now I use it more intensively.I stumbled on this problem somewhat by chance.
OK can’t try now but will experiment with my Win 10 laptop tomorrow to see if I can repeat this, unless someone else can find an answer. One possibility is to do the backup into a sub directory on the second drive maybe.
Doing a backup in a sub-directory is not a possibility, since I want to mirror the base drive onto a second one. The directory structure must be identical on both drives, otherwise they are not a mirror of each other.
OK I have recreated your set up exactly the same on my Windows 10 Pro laptop with 2 USB drives with the same info on them and watching one as store. When I plug the other in nothing happens at all. The only way I can get the display of the folder being unavailable is by removing the watched USB drive.
Are these plugged directly into the machine or via a USB hub?
I can’t prove this without logs from the Roon core system, but I think it’s very likely that the problem here is that both USB drives have the same NTFS “Volume ID”, and Roon gets confused as you’ve seen. If you upload logs I can confirm, or you can try the fix blind:
You need to change the Volume ID of one of the two disappearing drives. To do this,
(For reference, this is the first thing I’d expect given “Roon only sees one of two drives” and, importantly, “both drives are the same model/size/etc USB from the same vendor”)
@ben Thanks a lot. You got it right! My 2 USB external drives had the same “Volume ID”. Assigning new ID to the 2nd drive with the utility you pointed to me solved the issue.
But this begs a second question. If the Roon database refers to my media through a unique VolumeID, what will happen if (following a disk crash for ex.) I replace an external disk with a copy holding the same exact directory structure but with a different ID ? Will the database still behave correctly or will it have to be carefully updated using a special procedure ? If the disk used as a replacement had the same Volume ID, I guess Roon would use it without any problem. This is an important issue for me, as my meda library is somewhat extensive (60K tracks, 3K albums).
No there is only a problem if 2 disks have the same volume ID if the new disk has a different one re mapping the drive in the storage tab will reconnect with all your media.
