Crazy nightly memory usage spikes (50% of 16 GB), please help.
Posted Apr 1, 2023, 11:08 AM UTC
5125
Oh wait, I think I have figured it out!!!
It could be a DVR recording. Footy season is back.
#Thanks for your help everyone
41
I was going to suggest media indexing.
9
Hahaha, that’s amusing. Glad you found it, hilarious you were looking for the complex answer. Tip, never look at one metric.
5
Are you using a tv tuner with plex and /dev/shm as your temp_transcode directory or something?
2
Yep, that is exactly it.
1
Football is why I stopped doing ram transcoding. The dvr likes to put the whole recording in there and flush to disk at the end. Now I use a dedicated nvme disk.
1
Connect to it through SSH around 10pm and run top. Order the services by memory utilization.
9
htop is easier to view and interact with than top and the instructions you linked to are then unneeded.
With htop you can actually click the memory column with your mouse and it sorts intuitively like you’d expect when clicking a column. Basic top does not offer this.
11
btop is good too. Actually a mouse driven terminal app. I especially like the cpu graphs. Very handy on a six core hyperthreaded machine.
3
btop is good, however not included by default. That’s why I suggested htop.
3
True. Perhaps it will become more popular at some point. I remember when htop wasn’t included by default and all we had was top.
3
I love btop
2
or install an observability tool like NewRelic so you can go back and check data anytime.
I use a docker container and the NewRelic free tier.
2
What time of day would you like me to hack into your NAS then?
7
There is no „runaway“ RAM usage. RAM is there to be used. It does not waste itself, like a SSD does.
Linux is in general much better in controlling RAM use than Windows. There is nothing to be concerned about. In fact Linux uses free RAM (beside this report) always to buffer i/o data. So even when it shows as „unused“, it will still be utilized.
Good you learned what created the spikes, though.
6
[deleted]
1
Is it causing you an issue?
4
Good question, it hasn't caused any trouble that I have noticed but runaway RAM usage is rarely a good thing and I am trying to address any potential problems before they have larger consequences.
0†
It’s a good idea to understand what your system is doing but there’s no need to change anything right now.
Metrics are useful for revealing and understanding problems but if you’re not experiencing any difficulty then there may not be anything to fix.
Still, if you grok what is going on you might discover something that is a real problem— perhaps some task which isn’t executing properly.
Also, now that you know more about the regular rhythms of your NAS, you can factor that into future decisions. Eg, if you’re setting up a new cronjob maybe you pick a different time.
3
There was a press release put out by Synology this morning where concern was raised regarding suspected interdimensional entities seeking to harness the compute power of the Synology NAS line across the globe. They recommend that you turn the unit off after midnight, as most of the activity seems to occur during the wee hours of the night. Stay safe, brother. Also, happy April 1st.
3
Any help in trouble shooting would be appreciated. There is nothing obviously using massive amounts of RAM in the resource manager (applications or processes) and I have no idea how it 'reset's every night.
Has anyone else experienced this?
0
What’s the big deal anyway? RAM is there to be used. And 50% isn’t exactly earth shattering usage. Or is it you just want to know what’s using the RAM?
0
It was an increase in use of 50% of the RAM, taking it to almost 100% used. But also yes, I wanted to know what was causing the spike in use in case it was something that could get worse.
0
Obviously, some task starting every day around 8:00pm and finishing around 11:00pm.
Jellyfin ? Plex ? A backup task with compression? A game server? A library scan for updates?
I checked Plex and it isn't using that much RAM (and the regular tasks run at 3:00 AM), the jellyfin container is off at the moment. No game servers, and I can't think of what would be scanning.
Really is a head-scratcher.
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Update checks for DSM and various packages?