CHAPTER 9: HARD DRIVE TECHNOLOGIES

SATA Cable length

1 meter

SATA drives come in three common SATA-specific varies:

1.5 GBps, 3 Gps, and 6 Gps. which have a max throughput of 150 MBps, 300 MBps, and 600 MBps. It should be noted that if a system has an eSATA port, it will operate at the same revision and speed at the internal SATA ports.

PATA cable length

18 inches

eSATA cable length

2 meters

When you plug a SATA drive to a running Windows computer that does not have AHCI enabled, the drive doesn't appear automatically.

AHCI mode is enabled at the CMOS level and generally needs to be enabled beforee you install the OS.

AHCI was designed for spinning SATA drives to optimize read performance as well as to effect hot-swapping.

AHCI stand for Advance Host Controller Interface. AHCI is a hardware mechanism that allows software to communicate with Serial ATA (SATA) devices (such as host bus adapters) that are designed to offer features not offered by Parallel ATA (PATA) controllers, such as hot-plugging and native command queuing (NCQ).

You can connect up to two PATA drives, including hard drives, optical and tape drive to a single ATA controller. You set the jumpers on the drives to make one master and the other slave

ATA is a technology standard and it went through seven major revisions

You can add drive bay fans to prevent heat developing from the drive speeds. Drive bay fans sit at the front at the front of a bay and blow air across the drive

Airflow in a case can make or break your system stability. Hot systems can lock up.

RAID = Redundancy Array of Independent Disks

An array describes two or more drives working as a unit. They outlined several forms or levels of RAID that have since been numbered 0-6. Only a few RAID types are used today: 0. 1, 5, 6 and 0+1.

SATA 3.2

Another term for SATAe

Difference Between SATA and PATA. SATA (Serial ATA) and PATA (Parallel ATA) are two interfaces that are used to connect to mass storage devices like hard drives and optical drives. ... You'd be hard pressed to find PATA drives in your local computer stores because they now stock SATA ones

As SATA devices send data serially instead of in parallel, the SATA interfaces needs fewer physical wires - seven instead of 80 that was typical of PATA resulting in much thinner cabling. Thinner cabling means better cable control and better airflow through the PC case.

Data redundancy

Data redundancy is a condition created within a database or data storage technology in which the same piece of data is held in two separate places. This can mean two different fields within a single database, or two different spots in multiple software environments or platforms.

Solid State Drive (SSD)

Data storage device that uses flash memory to store data.

RAID 0 = Disk striping

Disk Striping requires at least two drives. It does not provide redundancy to data. If any one drive fails, all data is lost.

Duplexing is faster than mirroring but both are slower than the classic one-drive, one controller setup. You can use multiple drives to increase your hard drive access speed.

Disk striping (without parity) means spreading the data among multiple (at least twice) drives. By itself this provides no redundancy. If you save a small MS Word file, the file is split into multiple pieces; half of the pieces go on one drive and half on the other.

Disk Striping with parity protects data by adding extra information, called PARITY DATA than can be used to rebuild data if one of the drives fails.

Disk striping with parity requires at least three drives, but it is common to use more than three. Disk striping with parity combines the best of disk mirroring and plain disk striping. It protects that data and is quite fast. The majority of network servers use a type of disk striping with parity.

SATAe has unique connectors but provides full backward compability with earlier versions of SATA.

EXAM TIP: Each SATA is named for the revision to the SATA specification that introduced it, with the exception of SATAe. SATA 1.0: 1.5 SATA 2.0 3 Gbps SATA 3.0 6 Gbps SATA 3.2 up to 16 Gbps also known as SATAe

ATA (advanced Technology attachment)

HDD controller designed to replace earlier components without need for AT BIOS, also known as IDE drives comes in PATA and SATA.

RAID controllers aren't just for internal drives; some models can handle multiple eSATA drives configured at any of the RAID levels. You can create a RAID array using both internal and external SATA drives

INSTALLING DRIVES

RAID 6 = Disk Striping with Extra Parity

If you lose a hard drive in a RAID 5 array, your data is at great risk until you replace the bad hard drive and rebuild the array, RAID 6 is RAID 5 with extra parity information. RAID 6 needs at least five drives, but in exchange you can lose up to two drives at the same time. RAID 6 is gaining in popularity for those willing to use larger arrays.

If you have a Desktop with no eSATA external connector, you can install an eSATA HBA PCIe card or eSATA internal to external slot plate. There are also USB to eSATA adapter plugs.

Install eSATA, PCIe, PC Card or ExpressCard following the same rules and precautions for installing any expansion device.

RAID 5 = Disk Striping with Distributed Parity

Instead of dedicated data and parity drives, RAID 5 distributes data and parity information evenly across all drives. This is the fastest way to provide data redundancy. RAID 5 is by far the most common RAID implementation and requires at least three drives. RAID 5 arrays effectively use one drive's worth of space for parity. If, for example, you have three 2-TB drives, your total storage capacity is 4 TB. If you have four 2-TB drives, your total capacity is 6 TB.

JBOD = just a bunch of disks (or drives).

It is a real term for a storage system composed of multiple independent disks of various sizes. Many popular drive controllers support JBOD.

Most drives have a diagram on the housing that explains how to set the jumpers properly.

Jumpers can be used for diagnostics at manf plant or for special settings in other kinds of devices that use hard drives. Often master and single drive are the same setting on the hard drive although some drives require separate settings

EXAM TIP: KNOW YOUR CABLE LENGTHS

KNOW YOUR CABLE LENGTHS

RAID 0 + 1 = Nested, Mirrored Stripes

Like RAID 10, Raid 0-1 (or a mirror of stripes) is a nested set of arrays that works in opposite configuration from RAID 10. It takes a min of four drives to implement RAID 0 + 1. Start with two RAID 0 striped arrays, then mirror the two arrrays to each other.

In choosing your drive, first decide where you are going to put the device. Look for an open ATA connection. Is it PATA or SATA? It is dedicated RAID controller? Many motherboards with built-in RAID controllers have a CMOS setting that enables you to turn the RAID controller one or off.

Make sure you h ave room for the drive in the case. Where will you place it? Do you have a spare power connector? Will the data and power cables reach the drive? A quest test fit is always a good idea.

The aluminum platters are coated with a magnetic medium. Two tiny read/write heads service each platter, one to read the top of the latter and the other to read the bottom of the platter

Many refer to traditional HDDs as MAGNETIC HARD DRIVES or PLATTER-BASED HARD DRIVES

RAID = Redundant array of independent (or inexpensive) disks (RAID)

Method for creating fault-intolerance storage system. RAID uses multiple hard drives in various configuration to offer differing levels of speed/data redundancy. Short for Redundant Array of Inexpensive Disks, RAID is an assortment of hard drives connected and setup in ways to help protect or speed up the performance of a computer's disk storage. RAID is commonly used on servers and high performance computers

Disk Striping with parity

Method for providing fault tolerance by writing data across multiple drives and then including an additional drive, called a parity drive, that stores information to rebuild the data contained on other drives

Hardware RAID centers on an INTELLIGENT controller, either a PATA or SATA controller that handles all of the RAID functions. Unlike regular PATA/SATA controllers, these controllers have chips with their own processor and memory: this allows the card, instead of the OS, to handle all of the work of implementing RAID.

Most RAID setups are hardware-based. Almost all hardware RAID solutions provide HOT SWAPPING, the ability to replace a bad drive without disturbing the operating system. Common in hardware RAID.

SATA Express (SATAe)

Newest version of SATA that ties capable drivers directly into the PCI Express bus on motherboards

RAID 0 (striping) two or more non-redundant drives, fast but not really safe, both drives are assigned the same drive letter.

Only advantage of disk striping is speed. But if either drive fails, ALL data is lost.

Disk Striping

Process by which data is spread among multiple (at least two) drives. Increases speed for both reads and writers of data. Considered RAID level 0 because it does not provide fault tolerance.

Disk mirroring

Process by which data written simultaneously to two or more disk drives. Read and write speed is decreased but redundancy in case of catastrophe is increased.

Autodection

Process through which new disks are automatically recognized by the BIOS

External drives connect to a FireWire, USB, eSATA or Thunderbolt port.

Protecting your data with RAID

RAID

RAID (redundant array of independent disks) is a data storage virtualization technology that combines multiple physical disk drive components into a single logical unit for the purposes of data redundancy, performance improvement, or both. Data is distributed across the drives in one of several ways, referred to as RAID levels, depending on the required level of redundancy and performance. The different schemes, or data distribution layouts, are named by the word RAID followed by a number, for example RAID 0 or RAID 1. Each schema, or RAID level, provides a different balance among the key goals: reliability, availability, performance, and capacity. RAID levels greater than RAID 0 provide protection against unrecoverable sector read errors, as well as against failures of whole physical drives.

RAID 1 = Disk Mirroring/Duplexing

RAID 1 arrays require at least two hard drives, although they also work with any even number of drives. RAID 1 is the ultimate in safety but you lose storage space because the data is duplicated. You need 2-TB drives to store 2 TB of data.

EXAM TIP: Be familiar with common RAID levels, the minimum number of drives in a given level array and how many failures a given array can withstand and remain functional.

RAID LEVEL Min Drives No. FunctDrive RAID 0 2 0 RAID 1 2 1 RAID 5 3 1 RAID 6 5 2 RAID 10 4 Up to 2 RAID 0 + 1 4 Up to 2

RAID 10 = Nested, Striped Mirrors

RAID levels have been combined to achieve multiple benefits, including speed, capacity, and reliability, but those benefits must be purchased at a cost, and that cost is efficiency. take for instance RAID 10, also called RAID 1 + 0 and sometimes a "stripe of mirrors." Requiring a minimium of four drives, a pair of drives is configured as a mirror, and then the same is done to another pair to achieve a pair of RAID 1 arrays. The arrays look like single drives to the operating system or RAID controller. So, now with two drives, we can block stripe across the two mirrored pairs (RAID 0). We get the speed of striping and the reliability of mirroring at the cost of installing two bytes of storage for every byte of data saved. Need more space? Add another mirrorwed pair to the striped arrays?

redundancy

Redundancy is a system design in which a component is duplicated so if it fails there will be a backup.

SATA creates a point to point connection between the SATA device - hard disk. CD Rom, CD-RW, DVD-ROM, etc. and the SATA controller - the HOST BUS ADAPTER (HBA)

SATA devices look identical to PATA devices but are significantly different.

SATA-device cable length is more than twice of an IDE cable, about 40 inches (1 meter) instead of 18 inches. This faciliations drive installation in larger cases

SATA did away from the master/slave concept. Each drive connects to one port. No max number of drives. Snap in a SATA HBA and load em up.

SATAe ties capable drives directly into the PCI Express bus on motherboards.

SATAe drops both the SATA link and transport layers, embracing the full performance of PCIe. The lack of overheard greatly enhances the speed of SATA throughput, with each lane of PCIe 3.0 capable of handling up to 8 Gbps of data throughput. A drive grabbing two lanes could move a whopping 16 Gbps through the bus.

ATA-3 introduced Self Monitoring and Reporting Technology = S.M.A.R.T.

SMART is an internal drive program that tracks errors error conditions within the drive. The information is stored in nonvolatile memory on the drive and must be examined externally with SMART reader software.

SSD technology and devices are based on the combo of semiconductors and transistors used to create electrical components with no moving parts. In simple terms, SSDs use memory chips to store datga instead of all the metal spinning parts used in platter-based hard drives.

SSD technology is commonly used in desktop and laptop hard drives, memory cards, cameras, USB thumb drives and other handheld devices

Non-Volatile Memory Express (NVMe)

SSD technology that supports a communication connection between the OS and the SSD directly through a PCIe bus lane, reducing latency and taking advantage of the speed of high ends SSDs. NVME SSDscome in a couple of formats, such as an add-on expansion card and a 2.5 inch drive like a SATA drives for portables. NVME drives are lot more expensive currently that other SSDs, but offer much higher speeds

Current SSDS use nonvolatile flash memory such as NAND that retains data when the power is turned off/disconnected.

SSDs are more expensive and have an efficient single-level cell SLC technology. The cutting edge memory in SSD is STACKED MEMORY.

SSD form factors are typical 1.8 inch or 2.5 inch when plugging into traditional hard drive parts.

SSDs can be PATA, SATA, eSATA or US for desktop systems. Some portable computers have mini-PC Express versions.

STACKED MEMORY is cutting edge memory in SSD which takes NAND and adds a third dimension to it, giving it increased density and capacity.

SSDs operate internally by writing data to a scattershot fashion to high-speed flash memory cells in accordance with the rules contained in the internal SSD controller. The process is hidden from the operating system by presenting an electronic facade to the OS that makes SSD appear to be a traditional cylinder/head/sector (CHS) drive

Regular usage of SMART software will help create a baseline or hard drive functionality to predict potential drive failure.

Serial ATA was a significant improvement over ATA, which was difficult to install and use. Serial ATA addressed those issues

External SATA (eSATA)

Serial ATA-based connector for external hard drives and optical drives

All RAID implementations break down into either hardware or software methods. Software is often used when price takes priority over performance. Hardware is used when you need speed along with data redundancy.

Software RAID does not require special controllers; you can use the regular ATA controllers or SATA controllers to make a software RAID array. But you do need "smart" software

Windows Disk management is not the only software RAID game in town. There are third party programs.

Software RAID means the operating system is in charge of all RAID functions . It works for small RAID solutions but tends to overwork your OS easily, creating slowdowns. When you really need to keep going, hardware RAID is the answer.

Most common software implementation of RAID is the built-in RAID software that comes with Windows.

The Disk Management program in Windows Server versions can configure drives for RAID 0.1 or 5 and it works with PATA or SATA. Disk Management in Windows Vista can only do RAID 0 while later Windows Disk Management can do Raid 0 and 1.

Windows OS defrag utilities don't do much on SSDs. The Windows TRIM function is built into Win7 and later versions is a periodic garbage collection system that seeks out SSD memory cells with deleted connects and erases them, making them available to speed up new write operations

The back of computer for connectors

Hot swapping entails two elements: the first being the capacity to plug a device into the computer without harming either and, second, once that device is safely attached, it will automatically be recognized and become a fully functionally component of the system. SATA handles hot swapping well.

The biggest news about SATA is data throughput. Receives data in serial bursts instead of paralell as PATA devices do. SATA's device's single stream of daa moves much faster than multiple streams of data coming from a parallel IDE device, up to 30 times faster.

Many PATA hard drives use a jumper setting called CABLE SELECT rather than master/slave.

The position on the cable determines which drive will be master or slave: master on the end, slave in the middle. For cable select to work with two drives, you must set both drives as cable select.

RAID levels describe different methods of providing data redundancy or enhancing the speed of data throughput to and from groups of hard drives.

The starting place for RAID is to connect at least two hard drives in some fashion to create a RAID array. Specialized RAID controller cards support RAID arrays of up to 15 drives. Once you have a number of hard drives, the question is whether to use hardware or software to control the array.

External SATA uses shielded cable in lengths up to 2 meters outside the PC and is hot-swappable

This extends SATA bus at full speed faster than USB connection.

Disk Duplexing

Type of disk mirroring using two separate controllers rather than one, faster than traditional mirroring

Channel

Used in a common method for numbering boot devices, the first boot device available is channel 1, the second is channel 2, and so on

RAID 5

Uses block-level and parity data striping. Requires three or more drives

Hard drive cables have a colored stripe that corresponds to the number-one pin - called PIN 1 on the connector.

You need to make certain that pin 1 on the controller is on the same wire as pin 1 on the hard drive. Failing to plug in the drive properly will also prevent the PC from recognizing the drive. Incorrectly setting the master/slave jumpers or cable to the hard drives it just won't work. You need to plug a Molex connector from the power supply into the drive. All modern PATA drives use a Molex connector.

Disk Duplexing

a super-drive mirroring technique is because one controller does not write to each piece of data twice.

MAGNETIC HARD DRIVES

a traditional hard disk drive (HDD) is composed of individual disks or PLATTERS with read/write heads on actuator arms controlled by a servo moto - all contained in a sealed case that prevents contamination by outside air

AHCI (Advanced Host Controller Interface)

an efficient way to work with SATA HBAs. Using AHCI unlocks some of the advanced features such as hot-swapping and native command queuing

PATA cables

are 40 pin cables with 2 different types of ribbon attachments

Host Bus Adapter (HBA)

connects SATA devices to the expansion bus. Also known as the SATA controller.

HDD (Hard disk drive)

data recording system using solid disks (platters) of magnetic material at speeds to store/retrieve data. common speeds are 5400, 7200, 1000, 1500

PATA drives

data wire cable called ribbon. Dominated the industry for decades but not replaced by serial ATA drives that send data in serial using only one wire for data transfers implementation that integrates the controller on the disk itself

RAID 6

disk striping with extra parity, requires 5 or more drives Data is protected

Hybrid Hard Drives

drives that combine flash memory and spinning platters t provide fast and reliable storage. Shave boot time in half.

SATA (serial advanced technology attachment)

drives that send data in serial, using only one wire for data transers

eSATA (External SATA)

extends the SATA bus to external devices. These drives use connectors similar to internal SATA but they are keyed differently, look different.

HOW HARD DRIVES WORK

hard drives come in two major types: the traditional type with moving parts and a newer, more expensive technology that have no moving parts.

Spindle (or Rotational) Speed

hard drives run at a set spindle speed with the spinning platters measured in REVOLUTIONS PER MINUTE (RPM). How fast the disk on a HDD spins. New drives are hitting 15,000 RPM. The faster the spindle speed, the faster the controller can store and retrieve data. Common speeds are 5400, 7200, 1000, 1500

Hardware-based RAID is invisible to the OS and is configured in several configuration utility in FLASH ROM that you access after CMOS but before the OS loads.

he RAID option must be enabled in the BIOS before the system can load the RAID option ROM code. Press F2 during startup to enter the BIOS setup. To enable RAID, use one of the following methods, depending on your board model. Go to Configuration > SATA Drives, set Chipset SATA Mode to RAID. ... Press F10 to save and exit.

With additional drives, you have to plan on how to manage heat. See if there are built-in places to mount fans. Think about the noise level.

http://www.dummies.com/computers/pcs/how-to-set-jumpers-for-your-computers-ide-drive/

EXAM TIP: Get your hands on Windows 8.1 and/or Windows 7 to play with the Disk Management utilities. Get familiar with the RAID configuration and implementation procedures, as you may see these simulated on a performance-based exam question.

http://www.thegeekstuff.com/2010/08/raid-levels-tutorial

If you have two drives, set one to master and the other to slave. Or set both to cable select.

https://support.wdc.com/knowledgebase/answer.aspx?ID=981

Jumpers and Cabling on PATA Drives

if you have just one hard drive, set the drive jumpers to master or standalone

PATA (parallel ATA)

integrates controller on disk drive itself. Each controller supports 2 drives cable legnth = 18 inch.

Native Command Queuing (NCQ)

is a disk optimization feature for SATA drives. It enables faster read and write speeds. In computing, Native Command Queuing (NCQ) is an extension of the Serial ATA protocol allowing hard disk drives to internally optimize the order in which received read and write commands are executed.

grey end of the PATA cable

part of cable that plugs into the secondary drive

the short segment of the PATA cable

part of the cable that plugs into the drives (if the cable attachments are not color-coded)

Blue end of the PATA cable

part of the cable that plugs into the motherboard

the long segment of the PATA cable

part of the cable that plugs into the motherboard (if the cable attachments are not color-coded)

black end of the PATA cable

part of the cable that plugs into the primary drive

Hot-Swapping

replacing a bad drive in a RAID array without needing to reboot or power down.

RAID 0+1

requires 4 disks, effect of combining 2 RAID 1 disks. Provides both speed and redundancy

jumpers

small pin configuration on a drive

Parity drive

stores information to rebuild the data contained on the other drives. Requires at least three physical disks: two for the data and a third for the parity drive. This provides data redundancy at RAID levels 5, 10, and 0+1 with different options.

AHCI (advanced host controller interface)

tool for working with SATA HBAs. supports magnetic SATA drives

RAID 10

two mirrored RAID 0 configurations, needs at least 4 disks. Provides speed and redundancy

RAID 0

use byte-level striping and provides no fault tolerance

RAID 1

use mirroring or duplexing for increased data redundancy

IDE (integrated drive electronics)

when controlling electronics for a drive are handlined by the drive itself. A built in controller. All hard drives are technically IDE drivers.