Data deduplication has done much to optimize disk backup storage, but can those same efforts be successful in primary storage? Primary storage is, of course, different than secondary storage. Three of the approaches on the market today are in-line compression from companies such as Storwize or a post-process crawl approach performed by companies like Network Appliance. The mixed-mode approach of companies like Ocarina Networks chooses the best compression method for the file. Different levels of optimization can be chosen based on file type or age, allowing you to decide between highly optimized access and less compression.”]
Source: https://www.darkreading.com/database-security/optimizing-primary-storage