A month ago I was in Palo Alto seeing old friends and talking VMware. I spent some time with an old friend in performance engineering talking about vSphere’s implementation of linked clones. Conceptually I know linked clones require an additional map to translate the guest’s view of a contiguous file system into a reordered collection of blocks in multiple VMDK files. But I was not sure exactly how this technology worked and love hearing details. I want to share a few comments about this discussion.
VMware Linked Clone IO Implications
May 16th, 2011
May, 16 2011
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MLC Flash Versus SLC Flash
May 10th, 2011
May, 10 2011
EMC’s recent announcement at EMC World of Project Lightning documents a program to increase the use of flash devices in enterprise storage. The project includes increased use of flash storage in EMC arrays, all-flash storage configurations, and support for Multi-layer Cell (MLC) flash. This last subject–MLC flash and its difference from SLC flash–piqued my curiosity.
Many years ago I studied electrical engineering. I was an awful at it. Analog was never my thing. I much prefer ones and zeroes. But I challenge myself to think about electronics once every blue moon. So I decided to delve into SLC and MLC flash technologies to understand how they differ and why we should care. The content below summarizes my online research and the little bit I remember from school. If you can add, correct, or update this article I would be happy to have your comments.