Cache Volume utilized at around 50 % with proxy_cache_min_uses

[anish10dec]

With use of proxy_cache_min_uses volume of cache is getting settled up at
around 50% utilization. 
No matter what is the volume allocated in max_size its not filling up
further beyond 50%.
If the proxy_cache_min_uses is removed the cache gets filled up with
max_size allocated volume.

No of files in cache directory is far less beyond the size allocated in key
zone. Its getting capped up near 20 Lakhs whereas allocated key zone could
have accommodate around 80 L files with below configuration  

proxy_cache_path    /cache/contentcache keys_zone=content:1000m levels=1:2
max_size=1000g inactive=7d use_temp_path=off;

proxy_cache_min_uses 2;

Cache volume is utilized with above configuration is around 550 GB which is
not growing beyond and as inactive is set to 7d so this would have been
effective only after 7 days when content should have got deleted if not
accessed within 7 days time period. 

Writing all the objects on disk is causing high i/o so using
proxy_cache_min_uses would have been beneficial with utilizing cache
optimally and high cache hit ratio

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,289185,289185#msg-289185