Solved

What is a Disk Controller?

Posted on 2009-07-04
7
961 Views
Last Modified: 2012-05-07
Hello,

It's a pretty simple question I know.

When I hear the term "disk controller" I don't understand what's being referred to exactly.

So for example, I'm studying Oracle and they suggest putting the files on separate "Disks" as well as separate "Disk Controllers.'

I know what a hard disk is.

So in my PC for example, I have a 300 GB hard disk.
What would be its "disk controller?"

In a RAID setup for example, I can picture a set of different "hard disks", what would be its "disk controller?"

Is SCSI a disk controller?

Any feedback would be much appreciated.
Maximum points..
0
Comment
Question by:ora-what
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
7 Comments
 
LVL 96

Accepted Solution

by:
Lee W, MVP earned 500 total points
ID: 24778761
The disk controller is the device that is allowing the hard disk to interface with the rest of the system.  

Virtually all "consumer" systems, such as your home computer, has the controller build in to the motherboard - it's the electronics "behind" (metaphorically and not necessarily physically speaking) the SATA (or IDE) plug on the motherboard.

Oracle expects to be on a server.  Servers CAN have integrated controllers, but they often use separate I/O cards like this:
http://www.newegg.com/Product/Product.aspx?Item=N82E16816117043

So having separate controllers, you would need, obviously, two of these (controllers like these), where one drive is connected to each (or one set of RAID drives is connected to each).
0
 
LVL 31

Expert Comment

by:Frosty555
ID: 24778767
"Partitions" or "Logical Disks" refers to partitions on a single hard drive in the computer
"Physical Disks" or just "Disks" refers to the physical hard drives in the computer
"Disk Controller" refers to the interface or bus lines used to communicate with that physical hard drive.

So, as an example, with IDE drives your computer typicall has two IDE ports on it. Each IDE ribbon cable has two plugs on it. You can connect two hard drives to each IDE port, for a total of 4 hard drives in your system. In this case, you have two disk controllers (the primary and secondary IDE ports). And each disk controller can have two disks on it (the master and slave).

How bus lines are shared for sata devices... i'm not 100% sure. I expect that on the less expensive motherboards all the sata ports will share a single controller, but on more expensive motherboards you may have two or more controllers. Perhaps this is why on some motherboards you have 2 black sata ports and 2 red sata ports? I'm not sure, hopefully somebody else can clarify.
0
Why Off-Site Backups Are The Only Way To Go

You are probably backing up your data—but how and where? Ransomware is on the rise and there are variants that specifically target backups. Read on to discover why off-site is the way to go.

 
LVL 31

Expert Comment

by:Frosty555
ID: 24778772
I'm thinking that the whole idea behind Oracle suggesting you should put the files on separate disk controllers is that it provides one more layer of redundancy for failure situations. If your disk controller controlled several disks, and the controller went down, all disks on that controller would then cease to function. It's something to keep in mind when you are deciding where you files are going to go.

Also if several disks are communicating on one bus, they obviously have to share the bandwidth of that bus. There is more performance to be had if they were on separate buses.
0
 
LVL 32

Expert Comment

by:_
ID: 24778784
Disk Controllers are the part of the motherboard chipset that handles how many data channels you have, drives you can connect to each channel, and how the computer talks to the disk.

If you get an addon card, it has it's own chip that tell those same things.

IDE {PATA-SATA)
SCSI
SAS
RAID
are just different ways for the computer to talk to the drives. Sort of like a language.
0
 
LVL 32

Expert Comment

by:_
ID: 24778786
Wow!   Where did all those come from?  8 0
0
 
LVL 92

Expert Comment

by:nobus
ID: 24779743
0

Featured Post

Use Case: Protecting a Hybrid Cloud Infrastructure

Microsoft Azure is rapidly becoming the norm in dynamic IT environments. This document describes the challenges that organizations face when protecting data in a hybrid cloud IT environment and presents a use case to demonstrate how Acronis Backup protects all data.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article aims to explain the working of CircularLogArchiver. This tool was designed to solve the buildup of log file in cases where systems do not support circular logging or where circular logging is not enabled
Is your phone running out of space to hold pictures?  This article will show you quick tips on how to solve this problem.
This video teaches viewers how to encrypt an external drive that requires a password to read and edit the drive. All tasks are done in Disk Utility. Plug in the external drive you wish to encrypt: Make sure all previous data on the drive has been …
This is used to tweak the memory usage for your computer, it is used for servers more so than workstations but just be careful editing registry settings as it may cause irreversible results. I hold no responsibility for anything you do to the regist…

717 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question