Hi.
This is My first post so forgive me if this has been covered previously.
I’ve had My SSD Drives with all My Flac files connected externally to My NUCLEUSONE.
Twice this has happened in the last year Roon stops recognizing my files as if the Drives have been disconnected.
Luckily, I’ve backed up all my music so I could replace with new Drives.
However the Drives are recognized by WINDOWS 11 so the Drives are not faulty
Does anyone have any ideas as to what’s happening?
Are the drives formatted as NTFS? RoonOS is somewhat sensitive about this format - particularly if you are in the habit of moving them between the Nucleus One and a Windows PC. It’s important to always safely eject them from Windows - don’t just pull the USB cable out and attach it back to the Nucleus.
This implies that the drive is formatted NTFS. If the Nucleus is powered off without using the web interface (or a brief press of the power button), the drive may be marked as a “dirty volume” and requires a disk integrity check.
Unfortunately, the Nucleus cannot perform this function, to you need to do that on a Windows machine, and then cleaning unmount the drive from Windows.
Ideally, format the drive via the Nucleus web interface, and then copy your media files across the network. This would prevent the issue reoccurring, albeit it will take some time for the files to be copied.
For the sake of completeness, also don’t pull the cable from a running Nucleus. Shut down the Nucleus before doing so. (This is necessary because there is no „eject safely“ option for the Nucleus)
Edit: as @mjw already said
Hi.
Thanks for your reply.
The Drives are formatted and left connected to my NUCLEUSONE 24/7.
Have had no issues, files Play then for no apparent reason not recognizing.
The files are still on the drives that’s how I checked by connected to Windows 11 laptop.
This is the second time this has happened.
I’m just intrigued as to why.
Otherwise Roon is great 
In which format though
The dives were formatted on My WINDOWS PC.
As the files were on the drive prior to installing them.
Should I reformat and let the NUCLEUSONE format them?
I would like to advise that these are not installed internally.
These are external SSD drives which do not need to be formatted by the NUCLEUSONE.
Sorry if there is any confusion.
NUCLEUSONE can read external SSD
This was evident from your most recent post. Consequently, they cannot be formatted using the Nucleus web interface.
It would be really helpful if you confirmed whether they use NTFS or exFAT. This may be done from the Windows machine.
Ideally, use exFAT since the Nucleus can handle volumes that are not unmounted cleanly.
These are probably NTFS formatted.
As of now both drives connected with flac files are both recognized by Roon OS.
I’ll monitor and post if recurring problems arise
Windows can format discs in different formats, NTFS, exFAT, FAT32, etc etc. How they work in a Linux environment (which is what your Nucleus is) depends upon the format used on the external drive.
It sounds like you used NTFS, or, the drives came formatted that way. This format can have issues as you’ve described with Linux, especially, if the PC (aka Nuclues) has been turned off incorrectly, like pulling the power, or, loss of power in the house, or, just pulling the usb cable out of the PC.
As mentioned this is quickly remedied by plugging it into a Windows PC to check (remember to eject the drive).
However, other formats are less susceptible to this issue, for example exFAT. I always suggest external drives be formatted to exFAT.
If you don’t know how to check on the format, turn off the Nucleus One, then move the drive to the Windows PC. Click on the This PC icon, which will bring up all the attached drives. In this case the drive called Archive_A is an external USB hard drive.
Right click on the drive to access the menu
Choose Properties and the Property screen should pop up.
Note what is says under File System. In this case the drive is formatted NTFS, like we suspect yours is.
Thanks for that detail.
I’ll refomat to fat32.
Many thanks for your help 
Remember to copy all the data OFF first. You will loose all data on the drive when you reformat.
And you do NOT want fat32, You want exFAT. Huge difference.
Ok
Thanks
