Index design question

Hi. I'm dennis in korea.

These days. I've been testing elasticsearch with our company's application.
I felt like it's really enjoying impressive performance, rock-solid stability and easily.

I have a design question what would be the most efficient way to index large sets.

For example.

2012.1 average rows : 6,000,000, sql data size : about 160GB
2012.2 average rows : 5,000,000, sql data size : about 170GB
2013.6 ~

Would it be more efficient to store the archived documents into a separate type
or into a separate index(a day or a month)?

If it store the archived documents into a separate index. then 365 indices. has it too many indices? (for a day : about 5GB)

Our H/W spec : Intel(R) Xeon(R) CPU E7-4850 2.00Ghz 2EA, 64GB, Disk Raid 5.

and our application use only reading and analysis on work.

Thanks so much for your help !!!