Memory issue on mount

Installing and Using OpenWrt Network and Wireless Configuration
1

Hello!,

So I was testing around with my nginx steam cache and I noticed that in Luci under memory usage it was increasing.

Now this doesn't sound strange to me that it increases, but what I noticed when I stopped nginx it did not drop the usage, but when I start to delete the cache files it dropped rapidly.

To verify again I used seq command to write on the mount and indeed it increased again and it did also not decrease, once I stoppped the write operation only and I deleted the file it went down.

Im confused why this is, as im sure its not mounted to /overlay or /tmp but it is still mounted via fstab via block-mount as /mnt/sda2.

click to expand fstab 
config global
	option anon_swap '0'
	option anon_mount '0'
	option auto_swap '1'
	option auto_mount '1'
	option delay_root '5'
	option check_fs '0'

config mount
	option target '/mnt/mmcblk0p1'
	option uuid '84173db5-fa99-e35a-95c6-28613cc79ea9'
	option enabled '0'

config mount
	option target '/'
	option uuid 'ff313567-e9f1-5a5d-9895-3ba130b4a864'
	option enabled '0'

config mount
	option target '/mnt/sda1'
	option uuid '4e2778c1-fb4c-4502-b6d7-54ab9572b7c0'
	option enabled '0'

config mount
      option target '/mnt/sda2'
      option uuid 'f27b34f5-d44a-46f5-aac8-5720fa24cd1c'
      option enabled '1'

config mount 'overlay'
	option target '/overlay'
	option uuid '4e2778c1-fb4c-4502-b6d7-54ab9572b7c0'
	option enabled '1'

I did already played with the nginx configuration a little, changed worker connections, also the worker_processes but I think the problem is deeper than just nginx now since I experienced the same behaviour with the seq command.

nginx.conf (main) 
# For more information on configuration, see:
#   * Official English Documentation: http://nginx.org/en/docs/

user nginx;
worker_processes auto;
#error_log /var/log/nginx/error.log;
pid /opt/nginx.pid;

events {
    worker_connections 100;
}

http {

    log_format  main  '$remote_addr - $remote_user [$time_local] "$request" '
                      '$status $body_bytes_sent "$http_referer" '
                      '"$http_user_agent" "$http_x_forwarded_for"';

    log_format steam_cache '$remote_addr - $upstream_cache_status [$time_local]  '
                    '"$host $request" $status $body_bytes_sent '
                    '"$http_referer" "$http_user_agent"';

    #access_log  /var/log/nginx/access.log  main;

    sendfile            on;
    tcp_nopush          on;
    tcp_nodelay         on;
    keepalive_timeout   65;
    types_hash_max_size 2048;
    server_tokens	off;

    include             /etc/nginx/mime.types;
    default_type        application/octet-stream;

    proxy_cache_path /mnt/sda2/cache/nginx/steamcache/depot/
			levels=2:2
			keys_zone=depot:10m
			max_size=5g
			inactive=365d;

    proxy_cache_key "$scheme$uri";
    
    # Load modular configuration files from the /etc/nginx/conf.d directory.
    # See http://nginx.org/en/docs/ngx_core_module.html#include
    # for more information.
    include /etc/nginx/conf.d/*.conf;

    server {
        listen       80 default_server;
        listen       [::]:80 default_server;
        server_name  _;
       # root         /usr/share/nginx/html;

        # Load configuration files for the default server block.
        include /etc/nginx/default.d/*.conf;

        location / {
        }

        error_page 404 /404.html;
            location = /40x.html {
        }

        error_page 500 502 503 504 /50x.html;
            location = /50x.html {
        }
    }
}
nginx-steam-cache.conf 
server {
		listen 80;
		server_name *.steamcontent.com;
		resolver 8.8.8.8;
		
		access_log /mnt/sda2/cache/nginx/steamcontent.access.log;
		error_log /mnt/sda2/cache/nginx/steamcontent.error.log;

		location / {
				proxy_next_upstream error timeout http_404;
				proxy_pass http://$host$uri$is_args$args;
				proxy_redirect off;

				proxy_set_header Host $host;
				#proxy_set_header X-Real-IP $remote_addr;
				#proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;

				proxy_cache depot;
				proxy_cache_valid 200 301 302 10m;
				proxy_cache_valid any 1y;
				proxy_cache_use_stale   error timeout invalid_header updating
							 http_500 http_502 http_503 http_504;

				add_header Host $host;
				add_header X-Mirror-Upstream-Status $upstream_status;
				add_header X-Mirror-Upstream-Response-Time $upstream_response_time;
				add_header X-Mirror-Status $upstream_cache_status;
				add_header X-Forwarded-Host $host;
                               
		}
}

I'm using a Mochabin where the mount is on a 1tb WD SA500 m.2 drive running on OpenWrt 22.03.3 r20028-43d71ad93e.

I'm sure I misunderstood something with mounting and I would like some help :slight_smile:

Thanks!