SSD endurance calculations

Hey there,

 
We are looking at beefing up our servers with SSD's. Some of you did some interesting tests with the Intel 320. So the idea came to make a RAID10 with four 600GB models.

 
I did however do some calculations with the current database server (220GB database, expected to grow to 1TB by the end of next year). I specifically looked at /proc/diskstat at the read/write figures. From there I could see a read/write ratio of 3:1, and I also saw a wopping 170GB of writes per day (for a database that currently grows 1GB per dag). That seems like an insanely high figure to me! How come? We do mostly inserts, hardly any updates, virtually no deletes.

 
Secondly, I also looked at the reliability figures of the Intel 320. They show 5 years of 20GB per day, meaning that it will hold up for about 200 days in our system. RAID 10 wil make 400 days of that, but this seems hardly a lot.. Am I missing something here?

 
Kind regards,

 
Christiaan