Roon scans storage folders despite "only on startup" setting (ref#OKTBFW)

[ajl (Anthony)]

Hi! What’s not quite right with Roon?

· None of the above quite fits

None of the above quite fits

· None of these quite match

Tell us what's going on

· I have my automatic rescan interval for folders in my storage location set to "only on startup." However, Roon regularly cycles through my storage folders, scanning them. When it does this, it often also interrupts playback - sometimes for a split second, sometimes for minutes. How do I get Roon to only scan on startup, given that the setting which specifies this doesn't work?

Tell us about your home network

· Router: TPLVX220G2VDD

[alex_h (Alex)]

Good day @ajl !

We’re sorry to see you have bumped into a problem with scanning.

Can you please share with us a screenshots with all the settings you have set up related to the scanning and we’ll have a look and advise on what could be modified ?

Thanks!

Regards.

[ajl (Anthony)]

Hi, thanks! Here is the main one: It is set like this for each of my storage folders, of which there are 19, located on my NAS. Roon itself runs on Small Green Computer Sonic Transporter I5 (gen3) (2017) with the latest updates running (with Roon and the Sonic’s firmware).

[ajl (Anthony)]

In case this is useful:

I have both of these on throttled because it seems to mean that most of the time the interruption caused by the scanning is just a momentary glitch. If I have them on full (like I used to, back in the day when this setup was younger), everything hangs while it does the work. This is partly why I want to stop the scanning except for when I want to do it manually.

[alex_h (Alex)]

Good day @ajl !

Thanks for sharing screenshots.

Can you please try to set the Background audio analysis speed to Off instead of throttled ? It might possibly solve your problem.

let us know please how did it work for you .

Regards.

[ajl (Anthony)]

Hi Alex - thanks for the advice, and I have taken these steps. But still Roon seems to kick in with a round of scanning, unprompted by me. It also seems to do it at the time of day when I’m most likely to be sitting and listening, which prompts another question: why does it pick that time, and can I change that? Notionally, yes, as the settings asks how frequently you want the scanning to occur - but in my case there seems to be no correlation between what the setting says and what Roon is doing!
thanks again.

[ajl (Anthony)]

Looking forward to hearing more after new years (posting now to keep the thread open over the break).

[vadim]

Hello @ajl,

Thank you for the clarification and for the screenshots.

One important thing to note here is that file scanning and library / audio analysis are two different background processes in Roon, controlled by separate settings.

File scanning (Storage → Rescan interval)

The “Only on startup” setting applies only to rescanning storage locations for file changes (new, removed, or modified files). When set this way, Roon will not periodically walk the storage folders unless the server is restarted or you manually trigger a rescan.

Library / audio analysis (Settings → Library)

What you’re describing — Roon cycling through albums and occasionally interrupting playback — aligns with library analysis, not storage rescanning.

Library analysis includes tasks such as:

• waveform and loudness analysis
• metadata validation
• internal database reconciliation

Even when analysis is set to Throttled, it is still running in the background — just at a reduced priority. “Throttled” does not disable analysis entirely.

Library size, memory usage, and system resources

Based on diagnostics from your system:

• RAM: ~8 GB
• Library size:
  • ~245,000 local tracks
  • ~17,000 albums
  • ~89,000 performers

This library size is well above what we typically recommend for a system with ~8 GB of RAM, particularly on older hardware.

From the server logs, we can also see that RoonServer frequently operates at 80–90% of available physical memory. While this does not indicate a memory leak or fault — memory is being released correctly by the system — it does mean the server is running with very little headroom.

==========================================================================================
FILE: RoonServer_log.01.txt
  --------------------------------------------------
  [RAM 1]  Start: 68 MB (at 12/23 22:36:07)
  [RAM 2]  PEAK:  7164 MB (at 12/23 22:40:39)
  [RAM 3]  END:   6559 MB (at 12/23 23:13:58)
  --------------------------------------------------
  [TREND]  Change over 37.9 min: +6491 MB
==========================================================================================
==========================================================================================
FILE: RoonServer_log.07.txt
  [EVENT]  Log Rotation (continuation of previous session)
  --------------------------------------------------
  [RAM 1]  Start: 7216 MB (at 12/22 19:06:39)
  [RAM 2]  PEAK:  7384 MB (at 12/22 19:50:02)
  [RAM 3]  END:   7384 MB (at 12/22 19:50:02)
  --------------------------------------------------
  [TREND]  Change over 43.4 min: +168 MB
  [WARN]   File ended at PEAK memory usage

==========================================================================================

In this state, normal background tasks (such as library analysis) can compete with playback and UI responsiveness. When that happens, brief interruptions or pauses can occur, especially during active analysis cycles.

In short: the behavior you’re seeing is consistent with high memory pressure caused by a very large library on a limited-RAM system, rather than a failure of the “only on startup” scanning setting.

What to try next

To fully stop this background activity and confirm whether it’s the cause of the interruptions, please try setting:

Settings → Library → Background audio analysis speed → On Demand

This will prevent analysis from running automatically and restrict it to times when you explicitly trigger it.

Once set to On Demand, please let us know:

• whether the background scanning/analysis behavior stops
• whether playback interruptions still occur during listening sessions

Also please consider the increasing of the RAM on your Roon server.

That will help us determine whether this behavior is expected given the size of the library and available memory, or whether there’s something else we should investigate further.

[ajl (Anthony)]

@vadim

What you’re describing — Roon cycling through albums and occasionally interrupting playback — aligns with library analysis, not storage rescanning.

Hi Vadim,

Thanks for this. I wonder though - when this happens, and the circle icon is spinning, when I click on the circle the screen that comes up is the “Adding Music to your library” screen, with a list of my storage locations, and the counter showing how many files it has imported, and the counter on how many files it is scanning in real time. This looks like storage rescanning, not library analysis, from over here. What do you think?

[ajl (Anthony)]

@vadim

This library size is well above what we typically recommend for a system with ~8 GB of RAM, particularly on older hardware.

Thanks for this observation - back in the day, it was state of the art! I run Roon on a Small Green Computer Sonic Transporter I5 (gen3) (2017). As I understand it, I can’t update the RAM in this. I’m contemplating changing systems, to run Roon on my NAS (Synology DS 1019+) after upgrading some of its capacities. (ie the RAM).

[ged_hickman1]

@ajl

Synology DS 1019+

I personally wouldn’t bother.
The Nas has a ten year old celeron with much worse single thread performance than an i3 of equivalent age and only goes up to 8gb of memory.

[ajl (Anthony)]

Thanks @ged_hickman1 - apparently it can go up to 16gb (despite this being unsupported), but your point is well made. So I might consider changing to a new NAS for Roon. Or I could replace the I5 Sonic and just add 8gb to the 1019+ (and possibly SSD cache if that would be considered helpful (I’ve got the built in adviser program on this running, to learn its view). (See here )
Thanks!

[benjamin]

Hey @ajl,

Thanks for the additional information!

@ajl

This looks like storage rescanning, not library analysis, from over here. What do you think?

Indeed, it does sound like files are being re-added to your library in the above scenario. Could you share a screenshot of this? I do see quite a few network-related shares in regard to your local library - are you able to see which share is seemingly adding new files?

Thank you!

[ajl (Anthony)]

Thanks Benjamin. I will try and get a screen shot. The challenge there is that because I don’t control when this scanning happens, to get a screen shot it needs to happen when I’m listening to music and when I have the computer/iPad etc open. I will do my best!

In terms of which share - I have all my music on a NAS. Roon accesses the music through 21 seperate storage folders. When this behaviour happens, it scans each folder in sequence.

You say that it seems like files are being “re-added” - this is an interesting point. I thought they were just being scanned, but the idea of re-adding explains something else that has been happening. The scanning process usually ends with one of two outcomes: after the choke, the pause in the music, the spinning wheel, and (sometimes) the “uh oh, something does not look right here” screen, everything comes back to normal, and I just have to hit play again and the track I was on picks up from where it left off (or it has been dropped but we start at the next track). The second outcome (and this is the interesting observation prompted by your “re-adding” comment": when everything comes back on stream, I have a screen which says something to the effect that the album (because I usually play from the album view) cannot be played because it has been deleted. Now, as soon as I click back to the main albums page, the album will be there. But perhaps the scanning process has actually removed it and re-added it and this is why it is consuming so much brain space??

(I should note here that I have also been adding a fair bit of new music myself over recent weeks and reorganising what music is in which folders).

What do you think? And I’ll try and catch a screen shot later (the behaviour seems to happen either every 12 or every 24 hours - most noticeably around 5-7pm, which is in about 12 hours from now!)

[benjamin]

Hi @ajl,

Got it, thanks for all the additional information! Based on this, I do think what @vadim pointed out above does align with the behavior:

@vadim

Based on diagnostics from your system:RAM: ~8 GBLibrary size:~245,000 local tracks~17,000 albums~89,000 performersThis library size is well above what we typically recommend for a system with ~8 GB of RAM,

I’d be very curious to see how things perform with either a smaller library size (temporarily) or on a more robust server machine. Let us know if this is something you’d be able to try!

[ajl (Anthony)]

Thanks Benjamin.
So I have ascertained that I can double the size of the RAM in my Synology 1019+, which I will do in coming days. We’ll see what happens then. I’m curious as to whether you or @vadim have a view on how much RAM is desirable for running a library of this size on a Synology (say, a DS 1525+). I’m clearly in upgrade territory and am gradually making plans.

Back to the current behaviour - apart from the performance issues, do you have a view about this adding/scanning behaviour? The underlying problem - that Roon is ignoring the setting to only scan on startup - is still not resolved. On Tuesday I changed my modem arrangements and spent the day dealing with the fallout, which included having to re-add all my storage folders due to an unexpected change in IP address. However, during this process I was able to confirm that the settings on each folder are to scan only on startup - and yet the daily scans and “adding music to your library” messaging behaviour continue.

thanks once again,
Anthony

[ajl (Anthony)]

And just after I wrote the above, Roon came to the party, started scanning and dropped my track. Here are the screen shots of the notifications that pop up when I click on the spinning wheel.

[benjamin]

Hi @ajl,

You have my apologies here - our diagnostic report only dates back to 01/08, and so we’re not able to review the timestamp you’ve shared above.

Have you been able to upgrade the RAM yet? If so, how are things performing?

We’ll be monitoring for your reply, thank you!

[ajl (Anthony)]

Hi Benjamin,
Thanks for reply, and hope you had some R&R over the recent period.
So I’ve concluded that the issues have nothing to do with audio analysis processes. I’ve had them turned off, and the same scanning and adding music to the library behaviour has continued. When I have turned them back on, there has been no performance issues in general, apart from when the scanning and adding music process kicks in. Right at the moment, I have background audio analysis on throttled going through 3000 tracks (on demand is listed as fast), and I am experiencing no performance issues as I listen to music.

However, as I say, each day - usually in the 4pm to 7pm local time Perth Western Australia window, the adding/scanning behaviour associated with the above screen shots kicks in, usually scanning each of my approx 20 storage folders, and this is when the performance issues kick in, with pauses and sometimes complete stalls (including of playback and access by remotes) until the scanning/adding process completes. I imagine you can pick this up on the logs, allowing for time zones, as it happens very predictably!

I have not been able to add the RAM - some slight confusion on my end about this. I cannot add RAM to the sonic transporter on which Roon runs. I intend to add RAM to the Synology box which holds my music files, but on my current setup I don’t think that is where the real issue is. That will help the Synology call up the music, I guess, but it’s not going to add processing power to Roon.

The real mystery remains why Roon is doing this in adding/scanning in the first place, especially as the folder settings indicate that It should only scan storage folders on start-up, not on a continuous 24 hour cycle (mostly it seems to do it once a day; sometimes it seems to do this in the mid-morning as well!). I’m curious as to why that is, and what triggers it.

So, that’s the update for now! Thanks.