Traditionally, persistence media has been a synonym for rotating disks — devices that are relatively naïve, providing basic read and write functionality with block-level atomicity. Rotating disks expose Logical Block Addresses (LBAs) that are statically mapped by the disk firmware to Physical Block Address (PBAs). The role of traditional disks has been limited to primarily providing power-safe durability, while the OS/hypervisor stack does the heavy lifting with regard to functionality for performance, crash consistency, redundancy, data services, recovery, etc. Flash technology has been a key disruption for traditional enterprise storage tiers — it exhibits two to three orders of magnitude improvement to latency and throughput. Besides the performance disruption of current NAND-based flash and future NVM incarnations (which is a topic for a future blog post), there is another important dimension with respect to the intelligence of these devices. As a brief background, NAND-based Flash devices implement a Flash Translation Layer (FTL) which maps the LBA to PBA. In contrast to traditional disks, this mapping is not static, but changes each time the block is written- i.e., out-of-place updates. This log-based FTL design arises from a physical necessity that requires erasing a flash page (a slow process) before it can [...]]>...
- View Press Release
- Visit VMware, Inc.
|
|
|
| Posted: December 13, 2014 |
By: Wissen Schwamm
|
| Recent VMware related news. |
|
Top 20 KB articles for vSAN, April 2020
|
|
Top 20 Articles for EUC, April 2020
|
|
Top 20 articles for Workspace One, April 2020
|
|
Top 20 articles for vRealize Operations Manager, April 2020
|
|
Top 20 articles for vRealize products, April 2020
|
|
+ View more VMware related news +
|
|
| |
|
|
