SSD Caching Software

SSDs and Server Consolidation

Consolidating Servers with SSDsA topic The SSD Guy often brings up in presentations is the fact that SSDs can be used in enterprise applications to reduce server count, a phenomenon often called: “Server Consolidation.”  This is a confusing issue, so it bears some explanation.

There are lots of ways to accelerate an I/O-bound application.  The most direct one is to speed up the I/O.  In the past this has involved some pretty elaborate ways of using HDDs in arrays with striping and short stroking.  Many of these arrays cost a half million dollars or more.

Another is to hide the slow I/O speed by Continue reading

OCZ: Three Solid State Storage Products in Three Weeks

OCZ's PCIe Z-DriveSSD maker OCZ has been on something of a tear recently, introducing three new solid state storage products in three weeks:

  • Two weeks ago the company introduced the Z-Drive R4 CloudServ PCIe SSD, designed for the data center, in single-card capacities ranging from 300GB-16TB.  This product can transfer data at multiple gigabytes per second rates to deliver over a million IOPS.
  • Last week saw the introduction of the OCZ-SANRAD VXL enterprise storage accelerator, after OCZ’s January acquisition of SANRAD.  This product is flash cache acceleration software for VMware ESX and Citrix Xen virtualized environments that allows Continue reading

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