Much like his appearance, Luigi's has changed over the years. In "Mario Kart 64", which voiced many characters for the first time, some characters had two different voices in relation to the region of the game. North American and European forms present a deep voice for Luigi, by Charles Martinet, who also voices Mario, Wario, Waluigi, and Toadsworth. The Japanese form uses a high, falsetto voice, by (then French translator at Nintendo) Julien Bardakoff. All forms of "Mario Party" present the high-pitched clips of Bardakoff from "Mario Kart 64". Luigi kept this higher voice in "Mario Party 2". In "Mario Golf", "Mario Tennis", and "Mario Party 3" his voice returned to normal. Since then, in all games but "" and "Super Smash Bros. Melee", Luigi has always had a medium-pitched voice. In "", Luigi's voice was the same high voice from the Japanese "Mario Kart 64". In "Super Smash Bros." and "Super Smash Bros. Melee", Luigi's voice is based on Mario's voice (with clips taken from "Super Mario 64"), with a higher pitch. In "Super Smash Bros. Brawl", he has his own voice clips instead of voice clips taken from Mario.
Playable only in two-player:
Playable in one-player or two-player:
RAID
RAID is an acronym that stands for Redundant Array of Inexpensive Disks or Redundant Array of Independent Disks. RAID is a term used in computing. With RAID, several hard disks are made into one logical disk. There are different ways this can be done. Each of the methods that puts the hard disks together has some benefits and drawbacks over using the drives as single disks, independent of each other. The main reasons why RAID is used are:
It is not possible to achieve all of these goals at the same time, so choices need to be made.
There are also some bad things:
Most of the work on RAID is based on a paper written in 1988.
Companies have used RAID systems to store their data since the technology was made. There are different ways in which RAID systems can be made. Since its discovery, the cost of building a RAID system has come down a lot. For this reason, even some computers and appliances that are used at home have some RAID functions. Such systems can be used to store music or movies, for example.
A hard disk is a part of a computer. Normal hard disks use magnetism to store information. When hard disks are used, they are available to the operating system. In Microsoft Windows, each hard disk will get a drive letter (starting with C:, A: or B: are reserved for floppy drives). Unix and Linux-like operating systems have a single-rooted directory tree. This means that people who use the computers sometimes do not know where the information is stored.(To be fair, a lot of Windows users don't know where their data is stored as well.)
In computing, the hard disks (which are hardware, and can be touched) are sometimes called "physical drives" or "physical disks". What the operating system shows the user is sometimes called "logical disk". A physical drive can be split into different sections, called disk partitions. Usually, each disk partition contains one file system. The operating system will show each partition like a logical disk.
Therefore, to the user, both the setup with many physical disks and the setup with many logical disks will look the same. The user cannot decide if a "logical disk" is the same as a physical disk, or if it simply is a part of the disk. Storage Area Networks (SANs) completely change this view. All that is visible of a SAN is a number of logical disks.
In the computer, data is organised in the form of bits and bytes. In most systems, 8 bits make up a byte. Computer memory uses electricity to store the data, hard disks use magnetism. Therefore, when data is "written" on a disk, the electric signal is converted into a magnetic one. When data is read from disk, the conversion is done in the other direction: An electrical signal is made from the polarity of a magnetic field.
A RAID array joins two or more hard disks so that they make a logical disk. There are different reasons why this is done. The most common ones are:
RAID is done by using special hardware or software on the computer. The joined hard disks will then look like one hard disk to the user. Most RAID levels increase the redundancy. This means that they store the data more often, or they store information on how to reconstruct the data. This allows for a number of disks to fail without the data being lost. When the failed disk is replaced, the data it should contain will be copied or rebuilt from the other disks of the system. This can take a long time. The time it takes depends on different factors, like the size of the array.
One of the reasons why many companies are using RAID is that the data in the array can simply be used. Those using the data need not be aware they are using RAID at all. When a failure occurred and the array is recovering, access to the data will be slower. Accessing the data during this time will also slow down the recovery process, but this is still much faster than not being able to work with the data at all.
Depending on the RAID level however, disks may not fail while the new disk is being prepared for use. A disk failing at that time will result in losing all the data in the array.
The different ways to join disks are called "RAID levels". A bigger number for the level is not necessarily better. Different RAID levels have different purposes. Some RAID levels need special disks and special controllers.
In 1978, a man called Norman Ken Ouchi, who worked at IBM, made a suggestion describing the plans for what would later become RAID 5. The plans also described something similar to RAID 1, as well as the protection of a part of RAID 4.
Workers at the University of Berkeley helped to plan out research in 1987. They were trying to make it possible for RAID technology to recognize two hard drives instead of one. They found that when RAID technology had two hard drives, it had much better storage than with only one hard drive. However, it crashed much more often.
In 1988, the different types of RAID (1 to 5), were written about by David Patterson, Garth Gibson and Randy Katz in their article, called "A Case for Redundant Arrays of Inexpensive Disks (RAID)". This article was the first to call the new technology RAID and the name became official.
RAID uses a few basic ideas, which were described in the article "RAID: High-Performance, Reliable Secondary Storage" by Peter Chen and others, published in 1994.
Caching is a technology that also has its uses in RAID systems. There are different kinds of caches that are used in RAID systems:
In modern systems, a write request is shown as done when the data has been written to the cache. This does not mean that the data has been written to the disk. Requests from the cache are not necessarily handled in the same order that they were written to the cache. This makes it possible that, if the system fails, sometimes some data has not been written to the disk involved. For this reason, many systems have a cache that is backed by a battery.
When talking about a mirror, this is a very simple idea. Instead of the data being in only one place, there are several copies of the data. These copies usually are on different hard disks (or disk partitions). If there are two copies, one of them can fail without the data being affected (as it still is on the other copy). Mirroring can also give a boost when reading data. It will always be taken from the fastest disk that responds. Writing data is slower though, because all disks need to be updated.
With striping, the data is split into different parts. These parts then end up on different disks (or disk partitions). This means that writing data is faster, as it can be done in parallel. This does not mean that there will not be faults, as each block of data is only found on one disk.