This might be a number of things from read permissions on the files, to the version of SMB and track metadata or just simple interference across the network.

• Is the TP-Link router the only (central) WiFi access point, or are you using any other wireless access points?
• Have you tried running the Sonos system on SonosNet to see if that makes any difference? (Ensure it’s channel is different to the routers 2.4Ghz band).
• Maybe check the mobile controller device is not having any issues communicating with local devices, such things as VPN, antivirus software etc; might be getting in the way.
• Check that the metadata in the library tracks look okay using tag editor software, such as MP3Tag etc.
• Check the share permissions and maybe try different versions of SMB - try version 2 perhaps, if the router allows that setting to be changed?
• Ensure the router has the latest firmware update and reboot it too. Maybe reboot the Sonos speakers aswell to refresh their connection to the LAN.
• Its sometimes worthwhile changing the routers WiFi channel, ensuring that it’s using a non-overlapping channel 1, 6 or 11 for the 2.4Ghz band..  if you do use wireless extenders then also put them on the same channel

So that’s a few things to perhaps try to begin with, to see if those may resolve your indexing issue.

First of all, thank you for the suggestions here. It’s really appreciated.

Apart from rebooting the Sonos system again, I think all of those look OK. The only one I’m not sure of is the track metadata suggestion. I have downloaded MP3Tag and I’ll see if there are any missing data but that’s a strange error message to throw up if it’s down to missing metadata.

If this fails then I think I’ll have to invest in a dedicated NAS drive I guess.

Hi @nashie 

Thanks for your post!

We are aware of an issue whereby Sonos is unable to index a music library stored on a USB drive connected to a router, and our developers are currently looking into it; however, there is currently no timeframe for a resolution.

Thank you very much for your reply Corry P. It’s good to know that this is a known-issue and if I can help your developers with system diagnostics or something please let me know.

Do you know whether the problem is limited to USB SSD drives?

Mine is a Samsung USB SSD. I don’t remember having problems previously when I was using a Samsung old-fashioned USB HDD a few years ago.

Hi @nashie 

As far as I am aware, it has nothing to do with the type of drive used - only that it is connected to a router.

Thanks. One last question - do you know how long this bug has been identified? 

I found another forum thread that discusses what appears to be the same issue - https://www.snbforums.com/threads/sonos-and-usb-attached-hdd-drive-issue.79102/

Hi @nashie 

About 6 months - that page you linked to describes the same issue. To be fair, it should be noted that those 6 months have been a particularly unusual time for us with some recently resolved, high-priority issues being our main focus, and this particular issue hasn’t affected very many of our customers. As previously mentioned, there’s no time frame for a resolution so please don’t infer from this that it’s being looked at right now.

A possible workaround for you might be to try SMB v1 - although inherently less secure, it should yield better results. Your router may not have this option, unfortunately. Another is to include less files, though that’s hardly ideal.

Should you wish to go down the NAS route, my personal recommendation would be to consider a SBC (Single Board Computer) like a Raspberry Pi - as you already have the physical storage, it’ll be a much cheaper option than a device being sold as a NAS. It will take more knowhow to set up, however, though there’s lots of help available online. Dedicated software like FreeNAS, for example, will make things a bit easier.

I hope this helps.

I wonder if a USB to Ethernet adapter would allow it to work when plugged into an Ethernet port on the router?  My best guess would be that this wouldn’t cure it, but I wouldn’t think it was impossible - it depends on the nature of the problem.

Unfortunately, my router doesn’t say which version of Samba it’s running let alone change it. The idea of a Raspberry Pi is an interesting one as I do have a Pi 2 model B floating around somewhere.

Thank you for your suggestions :)

Just chiming in… I am having a similar issue.  Like the OP, I have my music library on a drive attached via USB to my router.    For me, it starts skipping songs because it says it can’t find them, and then eventually it can’t find any songs.  As soon as I notice the symptoms, I find that I can’t update the music library with the error saying that the drive is “no longer available”, even though I can access the drive from every phone and computer in my house.

Removing the network drive and re-adding it usually works (although it takes a while for the initial update.

Hi BobRed0965

Unfortunately I still have the same problem you are describing. I can only hope that this little thread bump may increase the awareness of it and hopefully Sonos will fix it soon. It's very annoying.

@BobRed0965 , note that the Sonos speakers use a different method/path to connect to the library. The  Sonos system is using Linux and an SMB connection, and not going through the same connection method as your computers and mobile devices.

I understand that.  However, one of my laptops is running Ubuntu (Linux) and it is having no problem connecting via Samba either.  This issue appears to be specific to Sonos.

Which version of Samba are the three devices running? Sonos S1 runs only SMB1, Sonos S2 can run either SMB 2 or SMB 3. 

I’m just offering that as a potential issue, I don’t have enough data to claim that’s the answer to your particular case. Especially as it seems to be coming and going. I’d think if it was indeed the Samba version, it wouldn’t be occasional Likely Sonos would be able to see the details if you were to submit a diagnostic and call them about it. The frequency/reboot aspect really makes it feel to me like more of a connection issue, somewhere between the speakers and the NAS. 

This issue is getting worse. I’ve long given up on Sonos ever re-indexing the drive but now it randomly can’t access the drive to play songs at all. This means I need to unmount the drive from the router and remount it. 

And no, it’s not the drive. I use the drive all day for other tasks.

Is there any idea yet on when this issue is likely to get looked at? It’s pretty poor that Sonos no longer works with USB drives plugged into routers.

Thank You are am interested if Sonos can come up with a solution.  I have had it running some time ago on a previous generation APE router, so wondered if an system upgrades / new hardware has caused this?