Squid cache to a second HDD

**NethServer Version:7
How to configure the second HD for Squid Cache?

I think you should approach this in the default Linux way:
Add a disk or volume to fstab and create a mountpoint for that volume at the location where squid cache is located. (anyone knows where that is?)

# grep cache_dir /etc/squid/squid.conf
cache_dir aufs /var/spool/squid 100 16 256

Mount your device like @robb says but change the value for cache at squid.conf. Do it with a template please.
How to use template-system is written here.