Memory usage stuck high

[pcostax]

Hi all! hope you can assit me with this issue.

I recently purchased an AS1102T and populated both bays with 4TB NAS hdds from Seagate. Since I purchased it to have a personal cloud but also to run Home Assistant on it, I immediately started adding the apps I found useful.
What I found is that the RAM is constantly above 70~80%, peaking at higher than 90% (which was triggering alarms). Initially I thought this was due to the process of making picture thumbnails, hdd mirroring, etc., so I disabled the alerts.
As the memory use is still high after several weeks, I started to disable all the apps I previously installed (and removed a few), but RAM use is still quite high...
I have now disabled ALL installed apps (even 'ClamAV') and set HDDs to hibernate at 10min. I can hear these hibernate (as they restart if I try to access any file), but activity monitor still shows RAM at 68% (with CPU at 1% and HDD at 0...). The only running process shown is 'top'. Everything else is 'sleeping'.

With all this considered, WHY is RAM usage stuck high, if nothing is using it? Really getting confused with this...

ADM version is the latest: 4.2.0.RC81

[Nazar78]

It's most probably cache and buffers, should be ok unless you're running lots of apps for a 1GB RAM. Have a look at the Activity Monitor. You can also look for more details using some commands like `free` or `htop`.

[pcostax]

Thanks for the quick reply!
My issue is that, once I start enabling Home Assistant, DataSync, FFmpeg, Photo Gallery and Sounds/looks good, it often jumps over the 90% threshold and generates alarms... I can keep it disabled, but should the cache and buffers still use such high RAM after several hours of downtime?
Activity Monitor really only shows 'top' running, but I'm not familiar with using commands. Are you using ssh and putty to do that?

[Nazar78]

Yes using SSH. You can always adds up the total memory usage from the Activity Monitor. If you exceeds 50% then there's too much apps running.

[pcostax]

17x 'lighttpd' processes (all sleeping) but the total is around 76Mb. Strangely, adding all processes seems to be around 200Mb and not >600Mb as the memory screen shows (used: 627.43MB / cached: 0.00B / Buffer: 27.78MB / free: 268.86MB). No apps are running at this moment...
I also will try to do an ssh connection with putty for more details, but this is quite annoying...

[father.mande]

Hi,

To clear buffer and cache in memory and see result you can do in a terminal (root or sudo)

free -m && sync && echo 3 > /proc/sys/vm/drop_caches && free -m

internal free command is limited :
free ... -m = in mebibytes (x 1024) but -b bytes, -k (default) or -g gibibytes can be used as you prefer
Entware free command is the full GNU one (procps-ng-free) with all options

Philippe.

[pcostax]

Hi,

I tried connecting with ssh and doing that. No luck:
"
free -m && sync && echo 3 > /proc/sys/vm/drop_caches && free -m
total used free shared buff/cache available
Mem: 924 431 157 15 334 558
Swap: 2044 141 1903
-sh: can't create /proc/sys/vm/drop_caches: Permission denied
"
I've logged in with my own credentials (administrator level), but maybe I need higher permissions? possibly 'root'?
Any other commands I can try to have this better tested? I have stopped all installed apps and uninstalled the ironwolf disk app as well, but HDDs keep showing high use and memory over 70%...

Many thanks for all your help!
Pedro

[Nazar78]

You need privileged access, prefix those commands with `sudo` in front of them or the least recommended way by switching to root, `sudo su -` before running those commands.

[pcostax]

Hi Nazar78,

That helped
"
# free -m && sync && echo 3 > /proc/sys/vm/drop_caches && free -m
total used free shared buff/cache available
Mem: 924 561 158 48 204 526
Swap: 2044 6 2038
total used free shared buff/cache available
Mem: 924 102 765 48 55 660
Swap: 2044 6 2038
"
It got the memory down to 17%, but the disks were still permanently active (read/write). After a restart, disks are still active (same) and the memory went up again to 70%.

I guess I will need to open a ticket with support to troubleshoot this properly... Any other ideas?

Thanks again!
Pedro

[Nazar78]

As I said earlier if the memory is high due to cache and buffers then it's ok, the system will manage but you can't run too much apps.