Website design introduction

Website design is a process via which to transfer the software requirments into an express way of software website, that means, it is a collection to display specific relevant web pages made by Dreamweaver, Photoshop and other tools according to certain rules in the internet.Simply speaking, the site is a communication tool, like a bulletin board, as it can publish public information they want (information)through the website, or use the site to provide network services (network service).Through web browser, people could access the website, get the information they need (information) or enjoy the Internet services. It consists website domain name (commonly known as URLs), website source code and web space. Among them, domain name is similar to the house number of the Internet, which is used to identify and locate computers on the Internet hierarchy type character identifier, and corresponds to the computer’s Internet Protocol (IP) address. The website design is a edit process done by designers via tools such as Frontpage or Dreamweaver!

Some examples about the flash file systems

With the rapid development of electronic technology, the flash file system have become an indispensable part in people’s daily life. In some way it extremely enjoys our life. However, fewer people knows the type of them. So shall we introduce some examples.

One of the earliest flash file systems was Microsoft’s FFS2, for use with MS-DOS in the early 1990s.

Around 1994, the PCMCIA, an industry group, approved the Flash Translation Layer specification, which allowed a Linear Flash device to look like a FAT disk, but still have effective wear leveling. Other commercial systems such as FlashFX and FlashFX Pro by Datalight were created to avoid patent concerns with FTL.

JFFS was the first flash-specific file system for Linux, but it was quickly superseded by JFFS2, originally developed for NOR flash. Then YAFFS was released in 2002, dealing specifically with NAND flash, and JFFS2 was updated to support NAND flash too.

LogFS, another Linux flash-specific file system, is currently being developed to address the scalability issues of JFFS2.

Then there are some susbsytems often called flash file systems but are more truthfully block drivers since they do not actually have a file system interface. These include:

True flash file system or TrueFFS is a low level file system designed to run on a raw Solid-state drive (most modern consumer SSDs are not raw). TrueFFS implements error correction, bad block re-mapping and wear leveling. Externally, TrueFFS presents a normal hard disk interface.

TrueFFS was created by M-Systems (US patent 5404485 ), on well-known “DiskOnChip 2000” product line, who were acquired by Sandisk in 2006. A derivative of TrueFFS, called TFFS or TFFS-lite, is found in the VxWorks operating system, where it functions as a flash translation layer, not as a fully functional file system. A flash translation layer is used to adapt a fully functional file system to the constraints and restrictions imposed by flash memory devices.

ExtremeFFS is a technology being developed by SanDisk allowing for improved random write performance in flash memory compared to traditional systems such as TrueFFS. Sandisk claims that the technology improves random access speed in Solid-state drives by a factor of 100. The company plans on using ExtremeFFS in an upcoming Multi-level cell implementation of NAND flash memory.