# uname -a
Linux zfs 5.13.19-6-pve #1 SMP PVE 5.13.19-14 (Thu, 10 Mar 2022 16:24:52 +0100) x86_64 GNU/Linux
Model name: Intel(R) Atom(TM) CPU C3758 @ 2.20GHz
Networking Gear & Setup Details
Description of Issue
For the past several weeks, I have found that the Roon interface on my iphone is extremely slow. I have now taken a look at the logs in ~/.RoonServer/Logs/RoonServer_log.txt and observe a number of extremely slow responses from roonlabs.net servers. For example:
07/01 01:21:15 Debug: [easyhttp]  GET to https://search.roonlabs.net/1/search?q=nancy%20wilson%20heart&count=50&trace=true&c=qobuz-us returned after 14177 ms, status code: 200
07/01 01:21:15 Debug: [easyhttp]  GET to https://internetradio.roonlabs.net/2/api/stations/search?query=nancy wilson heart&count=50&format=msgpack& returned after 14200 ms, status code: 200
07/01 01:22:46 Debug: [easyhttp]  GET to https://search.roonlabs.net/1/search?q=nancy%20wilson%20daughter&count=50&trace=true&c=qobuz-us timed out after 15000 ms
07/01 01:22:46 Error: search service failed: Result[Status=NetworkTimeout]
07/01 01:22:46 Debug: [easyhttp]  GET to https://internetradio.roonlabs.net/2/api/stations/search?query=nancy wilson daughter&count=50&format=msgpack& returned after 15220 ms, status code: 200
I do not believe that these issues arise from my own network connectivity. For example, while simple requests to these same severs without authentication fail, the response from the endpoint occurs within 73ms:
$ time curl search.roonlabs.net
<head><title>308 Permanent Redirect</title></head>
<center><h1>308 Permanent Redirect</h1></center>
I’ve spent a bit more time looking into this and observe that these issues arise only when the Roon core has IPv6 connectivity to the internet. I cannot yet rationalize how this affects the various roonlabs.net endpoints as I do not see AAAA DNS records for any of the logged ^.*.roonlabs.net/ hostnames. I have not narrowed down whether an HTTP redirect occurs to another hostname that does have a AAAA record.
The Qobuz endpoints do have AAAA records but requests go unreplied. For example, the following packet received no response.
This specification falls way below the minimum requirement to run Roon Server. You’ll need an i3 or equivalent to satisfactorily experience Roon.
Also, running ZFS on a low-spec machine isn’t ideal; typically you should allocate 1 GB memory for every TB of storage over and above normal system requirements. So, a 4 TB mirror would need 8 GB plus 2-4 GB for Linux.
Sluggish response times is an indicator of an underpowered core.
Whilst you may want to check DNS as @wizardofoz suggests, I’d look for other bottlenecks, especially if your library has grown since starting out with Roon.
I do suspect, however, that the line of reasoning so far here is tilting at windmills.
I believe I already addressed aspects of this CPU in my prior response. Similarly, 15 second network responses have little to do with local CPU speed. To reiterate, the Intel Atom range varies widely in performance. This is, of course, true of the Intel Core i3 as well.
As for ZFS, you are correct to intuit from the hostname that I use ZFS. I disagree with your memory calculations and do not follow your position. FWIW, this host has 128GB of RAM.
Just checking in to inquire whether disabling IPv6 helped at all? As @wizardofoz and @Martin_Webster have mentioned you’re running your Core on an underpowered Core. From checking your diagnostics if appears that it only has 2gb of RAM as well.
If disabling IPv6 on your router doesn’t help I’m afraid you’re going to have to consider migrating your Core to another machine. I’m moving your thread to Tinkering, as choosing to continue on an underpowered machine qualifies as such. Thanks.
I can confirm that disabling IPv6 on this host (via /proc/sys/net/ipv6/conf/eth0/disable_ipv6) resolves this issue. While this is a “fix,” having IPv6 connectivity is not particularly unusual and should not cause Roon to fail to function.
I’m happy to help debug the network aspect of this by providing additional network traces.