Music Servers/External Drives

 In addition, SSD reads data without generating vibration and is supposed to give less electric noise that compromises SQ.

Yes, although  as I understand it, this isn't  an issue if you're only using an HDD for local library storage with Roon (and not as the location where Roon Core is installed).  In Roon's storage settings, you set a path to the device.  Then Roon continually monitors it for new files.  When it finds them, it integrates them into your Roon library. In that scenario, I don't believe Roon goes back to the HDD to read the data for real-time playback (again, assuming Roon Core is not installed to that HDD).

Roon makes it very easy to share a variety of locally networked storage devices and make them integrate seamlessly with streaming services (Tidal/Qobuz).

I host my local music library on a headless Mac Mini, my "Jukebox", which I access via Screen Sharing from a MacBook Pro.  Roon continuously monitors a folder on the Mac for updates. I store ripped CDs on the Mac, as well as music files purchased from HD Tracks, Qobuz, or other vendors.  Roon Core runs on a separate, dedicated music server (a sonicTransporter i9), although it also can run on the Mini.  Both the sonicTransporter and the Mini can run certain DSP applications such as HQ Player.

Some audiophiles dislike having a full-function computer in a HiFi system, especially one co-located with the main HiFi components.  I find it very useful and versatile. I don't notice any fan noise. Occasionally a DSP application fails to launch until I respond to a system event (such as an automatic software upgrade process).  Those interrupts can be minimized by turning off (or carefully scheduling) processes such as Time Machine backups.

I also have an SSD inside the sonicTransporter.  Lately I only use it to store a backup copy of music files, and have it disabled in Roon's storage settings.  At any rate, whether you're using a full-function computer, a NAS, an individual USB-attached SSD, etc.,, it does not need to be a device specifically made for audio files.  However, the Bluesound Vault is such a device, which you might want to check out if only to research what's possible.