Every data file has to be stored somewhere. In the case of Hotel Network, these files were stored in special rooms called Hard Disks.
When a file is required, a Bellboy removes the appropriate file and transfers it to the RAM for processing.
There are many storage rooms in Hotel Network. When one hard disk fills up, another room is used. A bunch of rooms is called JBOD – or Just a Bunch of Disks. They have no relation to each other, except they happen to be placed near one another.
The Bellboy is given the keys by the OS. The detectives assumed that information contained in simple hard disks couldn’t be that important, otherwise why rely on a mere Bellboy? There had to be some place else.
They found an underground vault with a guard sitting in front – an obnoxious tough guy who is lord of the vault.
This guy calls himself a Server. His job is to serve files that are asked for, by whoever needs them, as long as it is approved by the OS. Yeah, he’s scared of the OS, but he likes to believe he has a mind of his own.
A Server is something that serves files when needed.
Everybody calls the underground vault a Server, too; they almost seem the same. The Server has no place outside the vault anyway.
A storage that is connected to network through a server is called a NAS – or Network Attached Storage.
A server can also perform operations and run software by itself. However, in Hotel Network, the vault server was used as a NAS – its only job is to serve data files when asked for.
Well, if it walks like a computer and quacks like a computer, then it must be one, too, right? Typically a server is just a computer, with the key difference that a server is optimised to be connected to a network, and is forever ready to send and receive files over it.
We all recognize a personal computer when we see one:
A server looks like this:
If both are computers why do they look different? Take a look at this comparison:
The key is organization and storage space. A typical home or office puts a PC on a table. However, servers are usually used in tandem with other servers or hardware, and have to fit in places you wouldn’t believe.
The height of each drawer is actually a standard, so that one can always plan one’s space nicely.
This standard is designated by the letter U, called a Rack Unit, and it is 1.75 inches (44.45 mm) high. There are also standards for the width, mounting, etc. Take a look at the links for suggested reading for more details.
When we need a drawer that can’t be the size of 1U (one unit), we can always design a box that is 2U, 3U, 4U and so on – as long as they are standard multiples of U. Finally, it ends up looking like this:
See how the whole shebang is tucked neatly into a corner of the office? Here are some reasons to have a computer in server configuration:
- Wheels for portability
- Racks to save space
- Ease of maintenance
- Easy to manage cabling
- Better heat management
The OS is a crazy freak. In addition to the NAS and JBODs he also has a locker in his office – for the most critical of files.
It is connected only to his office. The rest of the hotel isn’t privy to it. He calls it a SAN – or Storage Area Network.
You might be thinking: What’s the difference?
A SAN has drives attached to servers or other computers in such a way that it appears as locally attached to the operating system, just like your typical hard disk in a PC. SANs are uncommon outside larger enterprises. With NAS it is clear that the storage is remote, and the NAS has a server.
A SAN doesn’t have a server like a NAS but is still designed to be connected to a network. This differentiates it from JBODs.
Regular disks (JBODs) connected to a computer or server are called Direct-Attached Storage – or DAS.
Wow – that’s a lot of information for the lowly paid detectives who weren’t looking for trouble. They asked the same question you are probably asking: If there was a SAN and a NAS in the hotel, then surely there must be more than one computer inside Hotel Network, right?
The hotel was more sinister than it first looked. What the heck is Hotel Network, really?
Links for Further Research: