Look for a NAS that supports SMB v1 and higher, as the Sonos library share needs to use that version of the protocol, but the current understanding is that Sonos will be supporting higher versions of SMB in the not too distant future for S2 systems, but not sure when that might be as they very rarely mention their development roadmap with specific dates etc.

I recall the Netgear NV+ NAS back in its day, as it had the most noisiest fan (like a jet engine). So I would perhaps go for something a little quieter too.. ha ha

By the way I don’t think the older Linux Kernel on some S1 products will support anything higher than SMB v1 as that has been muted around this forum in the past. So the expectation for the SMB update, when/if it does land, is that it will be for products attached to an S2 System only.

Synology NAS is what I am using for many years successfully with my SONOS devices. The latest software version DSM 7.0.1 supports SMB v1 and NTLMv1 Authentication needed for Sonos library share access. I suggest to create a user account with read only access to the folders with the stored music tracks.

Thank you! Yes the Netgear NAS was noisy but it was in the basement for years, then moved up to the family room later next to the TV. There’s always music playing in the house so we don’t even notice lol. 

Thank you I am also looking into Synology.

A sbc(single board computer) solution is worth considering. I have one with a 240gb ssd attached.  Silent and cheap, and fun to build and set up.  The new Odroid hc4 looks good. 

Rolling your own is cheap and easy, a Raspberry Pi Zero W is plenty of computer power, just add a thumb or other external drive for your music collection.

These instructions will work to get almost any Linux based computer to serve up Sonos compatible SMB v1 connections.

SMB v1 NAS for Sonos  https://stan-miller.livejournal.com/650.html