SSD Caching Software

New Seagate Hybrid Drives: 2x the Flash, 2x the I/O Speed

Seagate's Momentus XT Hybrid HDDSeagate has just announced an upgrade to the company’s Momentus XT hybrid HDD family.  Seagate announced in August that the company had already shipped over one million units of its first generation Momentus XT since its May 2010 introduction.

For those unaware of what a hybrid HDD is, the short answer is that it’s a way to get HDD capacities and SSD speeds at a price marginally higher than that of an HDD. Continue reading

SSDs and Caching

IBM: Effect of Data Placement on SSD EffectivenessOne of the SSD Guy’s favorite subjects is caching and SSDs.  This is because I wrote a book on processor caches in the early 1990s, and the advent of SSD caches in storage systems hearkens back to the technology detailed in that book.

Caching works well whenever there are two layers in the memory hierarchy since the fast expensive layer can replicate data in the slow inexpensive layer to accelerate the processor’s performance. Continue reading

An HDD Cache for an SSD?

University of TorontoA colleague – Isilon’s Rob Peglar – pointed out an interesting paper written by researchers at the University of Toronto in collaboration with Microsoft.  The paper makes a case for using an HDD to cache writes to an SSD to improve storage system performance.

“Wait a minute!” you say.  “An HDD as a cache for an SSD?  This can’t be possible!” Continue reading