Age replacement policy for hard disks and SSDs at servers

I'm planing an age replacement policy for our storage and servers. Most of them are for DBs and some for images (static content) so yes, they have an huge I/O everytime.

Also, we use Samsung 840 Pro SSDs for the RAID Controllers (PERC H700i) as CacheCade.

Are you guys managing the replacement of old hard drives and solid state drives?

We don't proactively replace disks.

Wait until they fail or report prefailure status. This is why you have (hardware) RAID, management agents, failure indication LEDs on the server and a monitoring solution.

Keeping your gear under warranty and maintain your support contracts (within reason), having cold spares of components that fail often (disks, power supplies, RAM) and proactively monitoring the environment will take you much farther.

We don't proactively replace disks either. Backblaze recently did a blog post on this subject. One should note that they primarily use consumer grade drives.