I am running Odoo 14.0E on Ubuntu 20.04. I have nginx configured on it and running ssl. Everything works well apart from backing up of databases (duplication and deleting works). 
I get this error.
Database backup error: [Errno 2] No such file or directory: '/tmp/tmppzfft3fl/filestore/checklist/7c/7c5be11de3effb8b0f10418334bb0319b24f4802'
Here is how my nginx configuration file looks.
# Odoo Upstreams
upstream odooserver {
server 127.0.0.1:8069;
}
# http to https redirection
server {
    listen 80;
    server_name xxx.xx.xx.xxx;
    return 301 https://xxx.xx.xx.xxx$request_uri;
}
server {
    listen 443 ssl;
    server_name xxx.xx.xx.xxx;
    access_log /var/log/nginx/odoo_access.log;
    error_log /var/log/nginx/odoo_error.log;
   # SSL
    ssl_certificate /etc/ssl/nginx/bundle.crt;
    ssl_certificate_key /etc/ssl/nginx/xxx.xx.xx.xxx.key;
   
    # Proxy settings
    proxy_read_timeout 720s;
    proxy_connect_timeout 720s;
    proxy_send_timeout 720s;
    proxy_set_header X-Forwarded-Host $host;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;
    proxy_set_header X-Real-IP $remote_addr;
    # Request for root domain
    location / {
       proxy_redirect off;
       proxy_pass http://odooserver;
    }
    # Cache static files
    location ~* /web/static/ {
        proxy_cache_valid 200 90m;
        proxy_buffering on;
        expires 864000;
        proxy_pass http://odooserver;
    }
    # Gzip Compression
    gzip_types text/css text/less text/plain text/xml application/xml application/json application/javascript;
    gzip on;
    client_max_body_size 500M;
    
}
Any ideas on what could be wrong here? TIA.
 
                        
I found the solution. It was a wrong configuration of workers vs memory in the odoo.conf file which was causing connection to database to close since workers were timing out. Had nothing to do with nginx.