write coalescing – The SSD Guy Blog

Kaminario’s Performance and 7-Year Flash Life Warranties

Today Kaminario added a performance guarantee and a 7-year warranty to its arsenal. The company introduced its “Consistency Under Failure Guarantee” which ensures customers will see no more than a 25% drop in performance during a system failure. This means that critical operations and applications can continue to run at near-standard performance despite the failure of an SSD or even an entire node. Kaminario president Dani Golan told The SSD Guy last week that this is a conservative guarantee, and that few customers see more than a 10% degradation during failure tests in their own production systems.

As for the 7-year flash endurance warranty, no matter which SSD Continue reading “Kaminario’s Performance and 7-Year Flash Life Warranties”

How Controllers Maximize SSD Life – External Data Buffering

Since NAND flash is weakened by erase/write cycles then it would make sense to try to reduce those cycles to prolong the life of an SSD right? That’s what external data buffers are designed to do.

There are many ways to use RAM (either a RAM internal to the SSD controller chip or a discrete DRAM chip on the SSD’s printed circuit card) to stage data in a way that will reduce erase/write cycles.

One is to perform a function called “Write Coalescing.” This involves Continue reading “How Controllers Maximize SSD Life – External Data Buffering”

How Controllers Maximize SSD Life

How do controllers maximize the life of an SSD? After all, MLC flash has a lifetime of only 10,000 erase/write cycles or fewer and that is a very small number compared to the write traffic an SSD is expected to see in a high-workload environment, especially in the enterprise. Still, MLC is becoming the norm in the enterprise.

How do they do that?

This is where SSD architects really earn their pay. There are eight basic techniques that The SSD Guy knows of to extend SSD life beyond Continue reading “How Controllers Maximize SSD Life”