The Cost of Compromise: #2 Short-stroking Storage

Posted by VIOLIN SYSTEMS on Jan 2, 2013 11:39:53 AM

Ok. Behave, now. While it gives us the serious giggles, short-stroking is a serious storage sin that most commit to boost storage performance.

Today we continue with the 11 things that people do to make their storage run faster.

So, what exactly is short-stroking in the context of storage? Well, it starts with the laws of physics. Legacy disk technology has physical constraints: to read or write to a sector on disk, the disk head must first physically travel to the correct track and then the disk must rotate to the correct sector. Short-stroking is a practice where only the outer edge of the disk platter is used, reducing the transit time of the head and increasing the throughput. In short, there is less space to cover, and hence faster reads and writes.

The cost of this compromise is that between 75% and 90% of the disk capacity is wasted just to remove one or two milliseconds of latency.  What is latency? Latency is the time it takes for a data block to be written to or retrieved from the storage device. Why is latency a big deal?  The lower the latency, the faster access time to the data, the more productivity all around.

What’s the alternative? Violin Systems. Flash Memory Arrays from Violin have microsecond latency and no moving parts, resulting in ultra-fast performance without the need to sacrifice capacity.  Read more about flash storage and database latency.



Topics: cost of compromise, short stroking