Why cannot the same path for cache used several times?

[itpp2012]

B.R. Wrote:
-------------------------------------------------------
> What is wrong in having configured:
> 
> proxy_cache_path /data/nginx/cache levels=1:2 keys_zone=one:10m;
> proxy_cache_path /data/nginx/cache levels=1:2 keys_zone=two:10m;

keys_zone is memory, the other a 'file' path, I could imagine a 'cachehash'
used could overwrite the other.

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,252340,252344#msg-252344