Comptia A+ Hard Drive Technologies
What is the maximum SATA device cable length?
1 meter
At what speed does the SATA 1.0 specification perform?
1.5 GBPS
What is the maximum PATA device cable length?
18 inches
What is the maximum eSATA device cable length?
2 meters
At what speed does the SATA 2.0 specification perform?
3.0 GBPS
The maximum SATA-device cable length is _______________ inches.
40
What type of cable does a 66 MBps or faster PATA drive require?
80-wire cable
Which ATA revision introduced Self-Monitoring, Analysis, and Reporting Technology (S.M.A.R.T.)?
ATA-3
What is S.M.A.R.T.?
ATA-3 introduced Self-Monitoring, Analysis, and Reporting Technology (S.M.A.R.T.), an internal drive program that tracks errors and error conditions within the drive. This information is stored in nonvolatile memory on the drive and can be examined externally with S.M.A.R.T. reader software.
Why is airflow an important consideration in system builds?
Airflow in a case can make or break your system stability, especially when you add new drives that increase the ambient temperature. Hot systems get flaky and lock up at odd moments.
Which PATA standard provides support for very large hard drives and what are the maximum capacities of supported storage size and data transfer speed?
Ans: The last PATA standard, called ATA/ATAPI-7, provides support for very large hard drives (144 petabytes [PB], a number greater than 144 million GB) at speeds up to 133 megabytes per second (MBps).
What is a first step in configuring controllers?
As a first step in configuring controllers, make certain they're enabled. Most controllers remain active, ready to automatically detect new drives, but you can disable them. Scan through your CMOS settings to locate the controller on/off options. This is also the time to check whether your onboard RAID controllers work in both RAID and non-RAID settings.
Advanced Host Controller Interface (AHCI) mode is enabled at the _______________ level and generally needs to be enabled before you install the operating system.
CMOS
Motherboards provide support for the SATA hard drive controllers via the system BIOS, but they require configuration in _______________ for the specific hard drives attached.
CMOS
What is the purpose of the Advanced Host Controller Interface (AHCI)?
Current versions of Windows support the Advanced Host Controller Interface (AHCI), an efficient way to work with SATA HBAs.
What tool can you use in Windows to configure and manage hard drives and RAID levels?
Disk Management
Which term refers to the mirroring technique in which each drive has its own controller?
Disk duplexing
What is disk duplexing?
Disk duplexing is a super-drive mirroring technique uses a separate controller for each drive.
_______________ (without parity) means spreading the data among multiple (at least two) drives.
Disk striping
What is disk striping without parity?
Disk striping without parity involves spreading the data among multiple (at least two) drives.
_______________ extends the SATA bus to external devices.
External SATA (eSATA)
What is the minimum number of drives needed to implement RAID 6?
Five
Describe four problems associated with the parallel ATA interface.
For all its longevity as the mass storage interface of choice for the PC, parallel ATA had these problems. The flat ribbon cables impeded airflow and could be a pain to insert properly. The cables had a limited length, only 18 inches. You could not hot-swap PATA drives. You had to shut down completely before installing or replacing a drive. The technology had simply reached the limits of what it could do in terms of throughput.
Briefly describe the spindle or rotational speed of a hard drive.
Hard drives run at a set spindle speed, with the spinning platters measured in revolutions per minute (RPM). Older drives ran at a speed of 3600 RPM, but new drives are hitting 15,000 RPM. The faster the spindle speed, the faster the controller can store and retrieve data. Here are the common speeds: 5400, 7200, 10,000, and 15,000 RPM.
Which term is a type of controller that has chips with its own processor and memory?
Hardware RAID intelligent controllers
_______________ is the ability to replace a bad drive without disturbing the operating system.
Hot-swapping
What are the two elements of hot swapping?
Hot-swapping entails two elements, the first being the capacity to plug a device into the computer without harming either. The second is that once the device is safely attached, it will be automatically recognized and become a fully functional component of the system.
How can you take advantage of eSATA in a desktop or laptop if an external connector does not exist?
If a desktop system does not have an eSATA external connector, or if you need more external SATA devices, you can install an eSATA HBA PCIe card or eSATA internal-to-external slot plate. You can similarly upgrade laptop systems to support external SATA devices by inserting an eSATA ExpressCard. There are also USB-to-eSATA adapter plugs.
What is autodetection?
If the controllers are enabled and the drive is properly connected, the drive should appear in CMOS through a process called autodetection. Autodetection is a powerful and handy feature that takes almost all of the work out of configuring hard drives.
What options are generally available if you do not see a label on the drive that tells you how to set the jumpers?
If you do not see a label on the drive that tells you how to set the jumpers, you have several options. First, look at the drive maker's Web site. Every drive manufacturer lists its drive jumper settings on the Web, although finding the information you want can take a while. Second, try phoning the hard drive maker directly. Unlike many other PC parts manufacturers, hard drive producers tend to stay in business for a long time and offer great technical support.
When installing PATA drives, how do you set the jumpers?
If you have only one hard drive, set the drive's jumpers to master or standalone. If you have two drives, set one to master and the other to slave. Or set both to cable select.
Why is it easier to install a SATA drive instead of a PATA device?
Installing SATA hard disk drives is much easier than installing PATA devices because there's no master, slave, or cable select configuration to mess with. In fact, there are no jumper settings to worry about at all, as SATA supports only a single device per controller channel.
Describe how RAID 5 works.
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.
What is meant by just a bunch of disks (or drives), or JBOD?
JBOD is a storage system composed of multiple independent disks of various sizes. Many popular drive controllers support JBOD.
What two questions should be considered before installing or replacing an existing HDD with an SSD?
Keep in mind the following considerations before installing or replacing an existing HDD with an SSD: Do you have the appropriate drivers and firmware for the SSD? Do you have everything important backed up?
Briefly describe the various SSD memory technologies.
Less expensive SSDs typically implement less reliable multi-level cell (MLC) memory technology in place of the more efficient single-level cell (SLC) technology to cut costs. The cutting-edge memory in SSDs is stacked memory, which takes NAND and adds a third dimension to it, giving it increased density and capacity.
How do you install M.2 and mSATA drives?
M.2 and mSATA drives slip into their slot on the motherboard or add-on card, then either clip in place or secure with a tiny screw. Both standards are keyed, so you can't install them incorrectly.
What is the function of the cable select jumper setting?
Many PATA hard drives use a jumper setting called cable select rather than master or slave. As the name implies, 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 properly with two drives, you must set both drives as cable select.
What items can impede airflow?
Many things can impede the airflow—jumbled-up ribbon cables (used by older storage systems, USB headers, and other attachments), drives squished together in a tiny case, fans clogged by dust or animal hair, and so on.
Which term specifies a type of nonvolatile flash memory that current SSD devices use to retain data when power is turned off or disconnected?
NAND
_______________is a disk-optimization feature for SATA drives that enables faster read and write speeds.
Native command queuing (NCQ)
The _______________ specification supports a communication connection between the operating system and the SSD directly through a PCIe bus lane, reducing latency and taking full advantage of the wicked-fast speeds of high-end SSDs.
Non-Volatile Memory Express (NVMe)
How do you implement AHCI? List the available options.
On motherboards that support AHCI, you implement it in CMOS. You will generally have up to three options: IDE/SATA or compatibility mode, AHCI, or RAID. Use compatibility mode to install old operating systems, such as Windows XP. Going to AHCI or RAID enables the AHCI option for the HBA.
The latest version of SATA, SATA Express (SATAe) or SATA 3.2, ties capable drives directly into the _______________ bus on motherboards.
PCI Express
SSDs can install as add-on _______________ cards.
PCIe
Describe how RAID 0+1 works.
RAID 0+1 is known as 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 minimum of four drives to implement RAID 0+1. Start with two, RAID 0 striped arrays, and then mirror the two arrays to each other.
The Disk Management program in Windows Server versions can configure drives for _______________, and it works with PATA or SATA.
RAID 0, 1, or 5
Disk mirroring/duplexing is also known as _______________.
RAID 1
_______________ is also called RAID 1+0 and sometimes called a "stripe of mirrors."
RAID 10
RAID that distributes data and parity information evenly across all the drives is known as
RAID 5
Which unit measures hard drive spindle speed?
Revolutions per minute (RPM)
Which SATA variety runs at 6 GBPS?
SATA 3.0
Which SATA variety runs up to 16 GBPS?
SATA 3.2
How did SATA change autodetection?
SATA changed autodetection a little. Motherboards with SATA connectors use a numbering system—and every motherboard uses its own numbering system! One common numbering method uses the term channels for each controller. The first boot device is channel 1, the second is channel 2, and so on. So instead of names of drives, you see numbers.
Rather than using a master/slave concept, how does SATA function?
SATA did away with the entire master/slave concept. Each drive connects to one port. Further, there's no maximum number of drives—many motherboards today support up to eight SATA drives. If you want more than eight, you can snap in a SATA HBA and load the SATA drives.
What are the specifications and matching speeds of three common SATA-specific varieties?
SATA drives come in three common SATA-specific varieties: 1.5 Gbps, 3 Gbps, and 6 Gbps, which have a maximum throughput of 150 MBps, 300 MBps, and 600 MBps, respectively.
Which version of SATA ties capable drives directly into the PCI Express bus on motherboards?
SATAe
What hard drive technology typically implements a 1.8-, 2.5-, or rarely a 3.5-inch form factor?
SSD
You are installing two PATA drives. How should you set the jumpers?
Set one to master and the other to slave.
How many wires are in the SATA interface?
Seven
Which drive technology rules the roost in the server market?
Small computer system interface (SCSI)
What are the factors that make either software or hardware RAID the best choice?
Software RAID is often used when price takes priority over performance. Hardware RAID is used when you need speed along with data redundancy.
_______________ technology is commonly used in desktop and laptop hard drives, memory cards, cameras, USB thumb drives, and other handheld devices.
Solid-state
What type of power connector do all PATA drives use?
Standard Molex
Briefly describe the purpose of the Windows trim function.
The Windows trim function—built into Windows 7 and later versions—is a periodic garbage collection system that seeks out SSD memory cells with deleted contents and erases them, making them available to speed up new write operations.
What is the best friend a tech has when it comes to troubleshooting hard drive installation?
The best friend a tech has when it comes to troubleshooting hard drive installation is the autodetection feature of the CMOS setup utility.
Where is the obvious place to start when implementing RAID?
The obvious 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—plenty to support even the most complex RAID needs.
What is disk mirroring?
The process of reading and writing data at the same time to two drives is called disk mirroring.
What is the minimum number of drives needed to implement RAID 5?
Three
How many PATA drives—including hard drives, optical drives, and tape drives—can be connected to a single ATA controller?
Two
How many tiny read/write heads service each platter in a traditional hard disk drive (HDD)?
Two
How many functional failures can RAID 10 withstand and remain functional?
Up to two
What advanced SATA features does Advanced Host Controller Interface (AHCI) usage unlock?
Using AHCI unlocks some of the advanced features of SATA, such as hot-swapping and native command queuing
Describe the advantages of using disk duplexing over disk mirroring.
With two drives, each on a separate controller, the system will continue to operate even if the primary drive's controller stops working. Disk duplexing is also faster than disk mirroring because one controller does not write each piece of data twice.
How do you install solid state drives, including installation into a desktop or tower?
You install a solid-state drive as you would any PATA or SATA drive. They usually come in 2.5-inch laptop sizes. To install them into a desktop or tower with 3.5-inch drive bays, form-factor adapters are available to make the job easy.
How many failures can RAID 0 withstand and remain functional?
Zero
If the controllers are enabled and the drive is properly connected, the drive should appear in CMOS through a process called_______________.
autodetection
Windows can create partitions using the _______________ disk.
basic
A common SATA numbering method uses the term _______________ for each controller.
channels
The most important advance in SATA involves _______________.
data throughput
The process of reading and writing data at the same time to two drives is called _______________.
disk mirroring
Regardless of the external interface, you will find an ordinary SATA drive inside the _______________ (the name used to describe the casing of external hard drives).
external enclosure
Faster drives mean better system performance, but they can also cause the computer to_______________.
fans
To install solid-state drives into a desktop or tower with 3.5-inch drive bays, _______________ are available to make the job easy.
form-factor adapters
SATA creates a point-to-point connection between the SATA device and the SATA controller, the _______________.
host bus adapter (HBA)
Windows supports _______________, drives that combine flash memory and spinning platters to provide fast and reliable storage.
hybrid hard drives (HHDs)
ATA hard drives are often referred to as _______________ drives.
integrated drive electronics (IDE)
The _______________ on SATA controller and power cables makes it impossible to install either incorrectly.
keying
Which term represents a standardized form factor used in portable devices?
mSATA
A traditional hard disk drive (HDD) is composed of individual disks, or aluminum platters that are coated with a(n) _______________ medium.
magnetic
With a PATA hard drive that uses a jumper setting called cable select, the position at the end of the cable is the _______________ and the one in the middle is the slave.
master
Software RAID means the _______________ is in charge of all the RAID functions.
operating system (OS)
Disk striping with parity protects data by adding extra information, called _______________ data, that can be used to rebuild data if one of the drives fails.
parity
Hard drive cables have a colored stripe that corresponds to the number-one pin—called _______________—on the connector.
pin 1
Many folks refer to traditional HDDs as magnetic hard drives, or sometimes _______________-based hard drives.
platter
PATA drives dominated the industry for more than a decade, but have been replaced by _______________ drives that send data in serial, using only one wire for data transfers.
serial ATA (SATA)
In technical terms, _______________ technology and devices are based on the combination of semiconductors and transistors used to create electrical components with no moving parts.
solid-state
Hard drives run at a set _______________, with the spinning platters measured in revolutions per minute (RPM).
spindle speed
As per the PATA standard, if there is only one hard drive, the drive's jumper is set to master or _______________.
standalone
Disk _______________, spreading data across multiple drives, by itself provides no redundancy.
striping
