Chapter 9 Hard Drive Technologies

ATA-1 (ATA interface for Disk Drives)

- 1988 - Programmed Input / output - Parallel speed of 8.33 MBps.

ATA-2 (ATA Interface with Extensions-2)

- 1993 - Improved Programmed Input / output - Parallel speed of 16.67 MBps.

ATA-3 (ATA Interface-3)

- 1995 - Added S.M.A.R.T. - Parallel speed of 16.67 MBps. - DMA (Direct Memory Access) - ATA Security mode was added

ATA-4 / ATAPI-4 (ATA with Packet Interface Extension-4)

- 1996 - Introduced Advanced Technology Attachment Packet Interface. - Introduced added support to additional devices. - Ultra-DMA modes. - Started to see optical drives. - 33.33 MBps

ATA-5 (ATA with Packet Interface-5)

- 1998 - Saw 80-pin ATA connector introduced - Sped up UDMA - 66.67 MBps

ATA-6 / ATAPI-6 (ATA with Packet Interface-6)

- 2000 - added support for drives larger than 139.6GB. - 100 MBps

ATA-7 / ATAPI-7 (ATA with Packet Interface-7)

- 2001 - Introduced SATA-1 standard @ 150 MBps - Went from PATA to SATA - Introduced power connector 15-pin - increased speed. - 133 MBps in parallel speed & 150 MBps Serial Speed.

ATA / ATAPI-8

- 2004 - includes SATA but adds the newer 2.x & 3.x versions. - Marked the beginning of the end for the PATA Std. 133 MBps in Parallel & 600 MBps in Serial. - Minor revisions for PATA.

Native Command Queuing (NCQ)

- A disk optimization feature for SATA drives. It enables faster read and write speeds.

PIO (Programmed Input/Output)

- A transfer mode that uses the CPU to transfer data from the hard drive to memory.

parallel ATA (PATA) & serial ATA (SATA) drives

- ATA drives come in two basic flavors.

integrated drive electronics (IDE)

- ATA referred to as: - used to connect disk drives to a PC. - originally designed to connect a combined drive & controller directly to the 16-bit bus found in the 1984 vintage IBM PC-AT. - has 40 pins split across 2 long rows. - All hard drives are technically _______ drives, although we use the term ________ when discussing ATA drives.

AES (American Encryption Standard)

- ATA security has been augmented by drives that support internal encryption/decryption using the ________. Drives supporting ________ automatically encrypts all data that is written and automatically decrypts the data when erased. - No way to recover the data if you don't know the password.

* Jumbled up ribbon cables by old storage systems & other attachments. * Drives squished together in a tiny case * fans clogged by dust or animal hair

- Airflow can be impeded by:

* Power * Create lots of heat * Take up space * Wear down over time * Take a lot of nanoseconds to get things done

- All the moving parts of a platter-based drive use a lot of:

4-pin molex connector

- An IDE drive connects to the power supply via a:

actuator

- As the platters spin, an _________ moves the read/write heads across the platters.

RAID 6----Disk Striping with Extra Parity

- Basically its RAID 5 with extra parity information. - Needs at least 5 drives, but in exchange you can lose up to two drives at the same time. - Popular if your using larger arrays like 8 drives so that you have more redundancy by having 2 drives fail.

5400, 7,200, 10,000, & 15,000 RPM

- Common speeds:

NAND

- Current SSDs use nonvolatile flash memory such as _________ that retains data when power is turned off or disconnected.

RAID 5 (disk striping with distributed parity)

- Distributes data & parity information evenly across all drives. - Fastest way to provide data redundancy. - Most common RAID implementation & requires at least 3 drives. - effectively use one drive's worth of space for parity. - Write speeds are slow so you need a MB that supports dedicated RAID controller. - If for example, I have three 2-TB drives, my total storage capacity is 4 TB. If you have four 2-TB drives, your total capacity is 6 TB.

Common causes of RAID Failure include:

- Drive Failure - Controller Failure - Power issues - Software issues - RAID rebuild stress

* FireWire * USB * eSATA * Thunderbolt

- External drives connect to: - all these interfaces offer high data transfer rates and hot-swap capability, making them ideal for transporting huge files such as digital video clips.

Mini-SATA (mSATA)

- Form Factor specification developed by Intel for very small solid-state drives (SSDs), primarily in laptop or tablet systems. - _________ slot is often labeled "Intel Smart Response Technology."

* Traditional type aka magnetic hard drives, or sometimes called platter-based hard drives w/moving parts * Newer, more expensive technology with no moving parts called Solid State

- Hard Drives come in two major types:

pin 1

- Hard drive cables have a colored stripe that corresponds to the number-one pin---called _________ on the connector. - need to make certain that _________ on the controller is on the same wire as ___________ on the hard drive.

Revolutions per minute (RPM)

- Hard drives run at a set spindle speed, with the spinning platter measured in: - The faster the spindle speed, the faster the controller can store & retrieve data. - Faster drives mean better system performance, but can also cause computers to overheat especially in tight cases like minitowers. - Heat can cut the life of hard drives dramatically / 5 degrees Celsius rise can reduce life by as much as 2 years.

autodetection

- If the controllers are enabled & the drive is properly connected, the drive should appear in CMOS through a process called: - takes the work out of configuring hard drives.

Master or standalone

- If you have only one hard drive, set the jumpers to:

master (drive 0) , slave (drive 1), cable select

- If you have two drives, set one to ________ & the other to ___________. Or set both to __________.

the RAID array continues to work

- In RAID 1,5, & 10, if one drive fails,__ - but doesn't have data redundancy.

Spinning

- In order for an SSD to work with the OS, the SSD has to include some circuitry that the OS can see that makes the SSD appear to be a traditional ____________ drive.

The memory chips can also be:

- Installed on a PCI/PCIe card & plugged into a MB expansion slot. This implementation is used in some high-end workstations. - installed in a case that is similar in size & shape to a magnetic hard disk, then attached through the std IDE or SATA interface on the MB. This implementation is commonly used in laptop & desktop computers.

IDE or SATA connection

- Internal hard drives are connected to your computer via _____ or ______ interface connection.

Multi-level cell (MLC) Single-level cell (SLC)

- Less expensive SSDs typically implement less reliable _________ memory technology in place of the more efficient __________ technology to cut costs.

individual disks, or platters

- Magnetic hard drives contain one or more round aluminum or glass ____________ which are coated with several layers of various materials. - One of those layers can be magnetized or demagnetized to store binary data. - each piece of binary data is a bit. - If you have a hard disk with 20GB of storage space, it can magnetize or demagnetize 171,798,691,840 bits on the platters.

Binary number 1 Binary number 0

- Magnetized indicates the binary number ____. - Demagnetized indicates the binary number ______.

Controller Failure

- Most RAID implementations use a single RAID controller. - If the controller fails, the entire RAID array fails.

Benefits of Magnetic hard drives over SSDs:

- Older, established technology is more plentiful - Larger capacities available. - Does not have a max read/write limit. - Less expensive per byte.

read/write

- Once a __________________ operation is commenced, the virtual drive circuits pass the operation through a translator in the SSD that maps the true inner gusts of the SSD.

18 inches

- PATA cable length:

Most common Disk Drive form factors are:

- PC disk drive form factor is 3.5 inches. - Most common laptop disk drive form factor is 2.5-inches. - Lighter, thinner laptops might use a 1.8-inch form factor disk drive.

Power issues

- Problems with the power signal, such as surges or dirty power, can cause problems with the controller or one or more hard disks in your RAID array.

Hardware failure

- RAID guards against ________. - Always have current backups of all working disks in your RAID array.

RAID 1+0 (RAID 10) "Stripe of mirrors." A nested RAID level

- Requires a minimum of 4 drives. - a pair is configured as a mirror, and then the same is done to another pair to achieve a pair of RAID 1 arrays. - Arrays look like single drives to the OS or RAID controller. - With 2 drives, we can block stripe across the two mirrored pairs (RAID 0). - 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. - If a side with a mirror, then I lose my data because it is striped mirrored but it's really rare for that to happen.

RAID 1 - Disk Mirroring/Duplexing

- Requires at least 2 hard drives, although they also work with any even number of drives. - The ultimate in safety, but you lose storage space because the data is duplicated - Example is you would need two 2-TB drives to store 2 TB of data.

Benefits of SSDs over magnetic hard drives:

- Rugged - no moving parts to wear out or break. - Virtually silent. - Faster boot and data access speeds. - Not affected by fragmentation. - Smaller form factors available.

1 meter

- SATA cable length:

1. SATA 1.0: 1.5Gbps/150 MBps 2. SATA 2.0: 3Gbps/300 MBps 3. SATA 3.0: 6Gbps/600MBps 4. SATA 3.2: up to 16 Gbps, also known as SATAe

- SATA drives come in a common SATA-specific variety: - eSATA has same revision & speed as internal SATA ports.

15-pin SATA connector

- SATA drives connect to the power supply via a:

* 1.8-inch * 2.5 inch * or (rarely) 3.5 inch

- SSD form factors are typically _________ when plugged into traditional hard drive ports.

1 Drive or Standalone

- Single drive setting varies among manufacturers. Some use Single; others use:

Industry Standard Architecture (ISA) bus

- The AT bus is otherwise knowns as:

hardcards

- The earliest IDE drives were called _______ & were nothing more than hard disks & controller cards bolted directly together and plugged into a slot as a single unit. - Very thick and caused interference with adjacent cards.

Drive Failure

- The hard drives in a RAID array have more simultaneous data reads & writes than a typical hard drive. - This increases the amount of wear & tear on the drive. - If one drive in the array fails, the others take over until you get a replacement drive installed. This, in turn, increases their overall activity & the chance of a second ___________.

SATA Express (SATAe) AKA SATA 3.2

- The newest version of SATA that ties capable drives directly into the PCI Express bus on motherboards by dropping the SATA link & transport layer. - combines PCI Express signaling with the SATA software protocol (command set), plus a new set of cables and connectors that are backward compatible with SATA. - uses two PCIe lanes with up to 8Gbps / lane - Sends two bits at a time - Each lane of PCIe 3.0 is capable of handling up to 8 Gbps data throughput. - A SATAe drive grabbing two lanes, therefore, could move a whopping 16 Gbps through the bus. - backward compatibility with earlier version of SATA. - You need a MB w/SATAe support to take advantage.

Drive spindle

- The platters are mounted on a ____________ & rotate (spin on the spindle) in unison.

trim function

- The windows ___________ built into windows 7 & later versions is a periodic garbage collection system that seeks out SSD memory cells w/deleted contents and erases them, making them available to speed up new write operations.

embedded multi-media card (eMMC)

- This type of memory is referred to as: - is common implementation on small laptops, ultrabooks, most mobile phones & tablets.

S.M.A.R.T. (Smart Monitoring And Reporting Technology)

- Was introduced by ATA-3 - an internal drive pgm that tracks errors and error conditions within the drive. - Stored in non-volatile memory on the drive & must be examined externally with ___________ reader software. - Regular usage of this software will help you create a baseline of hard drive functionality to predict potential drive failures.

Direct Memory Access (DMA)

- When a device controller transfers an entire block of data from its own buffer storage to memory without CPU intervention - A ______ channel enables a device to transfer data without exposing the CPU to a work overload. - With _______ the CPU can process other tasks while data transfer is being performed. - Special channel btw RAM & fast speeds.

RAID rebuild stress

- When you lose a RAID drive, you replace the drive & rebuild its data from the parity information on the other drives. - The rebuild process is I/O intensive & increases the wear & tear on the existing drives. - If all the drives in your RAID array were purchased and installed at the same time, this additional stress could cause one of them to also fail.

Hybrid Hard Drives

- Windows support ____________, drives that combine flash memory & spinning platters to provide fast and reliable storage. - they can help shave boot times in half &, b/c the platters don't have to spin all the time, add 20-30 minutes more of battery life for portable computers. - a magnetic hard drive with flash memory chips added to it. - The flash memory chips act as a buffer for OS & application files, allowing the system to boot up & start applications faster. - give you the SSD benefit of increased boot & application access speeds, along with the large storage size benefit of a magnetic hard drive.

Drive bay fans

- You can deal with the warmth with these very fast drives by adding __________ b/w the drives or migrating to a more spacious case. - sit at the front of a bay and blow air across the drive.

PCI Express M.2

- a reduced-size version of SATA Express & is designed to replace the current mSATA standard. - M.2 cards can be used for SSDs & various classes of wireless networking or satellite navigation. - designed primarily for laptops & tablets & some high-performance desktop MBs feature it. - 2 types of interface logic it can use: PCI Express or SATA.

Software issues

- a virus or corrupt files.

Redundant Array of Independent (or inexpensive) Disks (RAID)

- allows you to configure multiple hard disks into a logical group to improve performance & add fault tolerance. - multiple drives for data protection & increased speeds. - An array describes 2 or more drives working as a unit. - different methods of providing data redundancy or enhancing the speed of data throughput to and from groups of hard drives.

disk duplexing (RAID I) with separate controller to speed up

- another version of RAID I - uses separate controller for each drive. - Fault tolerant - with 2 drives, each on a separate controller, the system will continue to operate even if the primary drive's controller stops working. - Faster & Safer - Exactly two (redundant) drives - Both drives are assigned the same drive letter.

* Appropriate drivers & firmware for the SSD and if you have everything backed up.

- before installing or replacing an existing HDD w/an SSD, you have to check for:

Host adapter or Host Bus Adapter (HBA) or Host Controller

- connects a computer, which acts as the host system to other network and storage devices. - Can be integrated to the MB or be on a separate expansion card. - We call a SCSI, PATA, or SATA card a ________ instead of a controller because the actual controllers are inside the drives. - You can think of a ___________ as a device that connects a controller to a bus.

Serial ATA (SATA) Characteristics

- creates a point-to-point connection b/w the SATA device, hard disk, CD-ROM, CD-RW, DVD-ROM, DVD-RW, BD-R, BD-RE & the SATA controller, the host bus adapter (HBA). - Much thinner cabling due to using fewer physical wires. - SATA connectors can be straight, right-angled, or left angled. Angled connectors allow for lower profile connections. - thinner cabling means better cable control & better airflow through the PC case, resulting in better cooling. - longer cable length up to 1 meter. - No master/slave technology. - handles hot-swapping.

Ribbon Cable

- data cable for PATA is called:

Software RAID

- does not require special controllers. - means OS is in charge of RAID functions. - you can use the regular ATA controllers or SATA controller to make a ______________. - it has to be smart software like disk management. - used when price takes priority over performance.

serial ATA (SATA)

- drives that send data in serial, using only one wire for data transfers. - it is AHCI enabled - Simple keyed connector - is a completely different physical interface design, but it is backward compatible on the software level with Parallel ATA (PATA). - When set in non-AHCI / RAID (in other words, IDE or legacy mode), ________ is software-compatible with PATA, which means it emulates all the commands, registers, & controls so existing software can run without changes.

2 meters

- eSATA cable length:

Advanced Host Controller Interface (AHCI)

- efficient way to work with SATA HBAs. - SATA advanced features such as command queuing, hot-plugging, and power management. - When you plug a SATA drive to a running windows computer that does not have this feature enabled, the drive doesn't appear automatically. - with feature enabled, the drive should appear in Computer immediately. - is enabled at the CMOS level and has to be enabled b4 you install OS. Enabling after installation causes windows to blue screen. - designed for spinning SATA drives to optimize read performance as well as to effect hot-swappability.

External SATA (eSATA)

- extends the SATA bus to external devices. - use connectors similar to internal SATA, but they're keyed differently so you can't mistake one for the other. - uses shielded cable (because it lives outside) in lengths up to 2 meters outside the PC & is hot-swappable. - it extends the SATA bus at full speed.

- advanced technology attachment (ATA)

- interface that now virtually monopolizes the hard drive market. - Also called IDE. - to connect hard drive to Motherboard directly instead of using a controller card. - Uses parallel communication.

Disk Drive

- is a computer component where hardware information, computer OS software, application software, & application data are stored. - this storage is non-volatile, meaning the info is maintained, regardless of whether or not there is power to the disk drive, until it is deleted by a software pgm or user.

ATAPI (Advanced Technology Attachment Packet Interface)

- is a std designed to provide commands necessary for devices such as optical drives, removable media drives such as SuperDisk & Zip, and tape drives that plug into an ordinary SATA or PATA (IDE) connector.

Cable Select

- jumper setting used by PATA hard drives rather than master or slave. - the position on the cable determines which drive will be master or slave: master on the end, slave in the middle. - for this setting to work properly with two drives you must set both drives as __________.

hot-swapping

- occurs when you replace a hard drive, or other component with a similar component while the computer or device remains in operation. - During _______, the computer's bus or I/O controller doesn't recognize that the original device has been removed and replaced with another device. - often used to replace a failing or failed drive in a RAID array. - ability to replace a bad drive without disturbing the OS.

SSDs characteristics

- operate internally by writing data in a scattershot fashion to high-speed flash memory cells in accordance w/the rules contained in the internal SSD controller. - Process is hidden from OS & makes it appear as a traditional cylinder/head/sector (CHS) drive. - SSD memory cells have finite # of times that they can be written to b4 wearing out. - 1st generation once data was written into a memory cell, it stayed there until the drive was full. - 1st generation of protection from this was to wait until all cells of an SSD were filled b4 erasing & reusing a previously written cell. - The result of this is like an electronic version of disk fragmentation. - defragmenting utilities for magnetic HDDs don't work for SSDs.

Memory chips can be:

- permanently installed on the MB.

read/write heads

- positioned over the top and bottom of each platter.

disk mirroring (RAID I)

- process of reading & writing data at the same time to two drives is called: - Fault tolerant - Read performance is improved due to the fact that any free drive in the array can provide the CPU with the data it requests. - Write is slower. - Slows things down - one drive would be the primary drive & the other mirror drive would not be used unless the primary drive failed. - exactly 2 (redundant) drives - safe but slow because one controller is writing to 2 drives. - Both drives are assigned the same drive letter.

Disk Striping with Parity / Raid - 5

- protects data by adding information, called parity data, that can be used to rebuild data if one of the drives fails. - Requires at least 3 drives - combines the best of disk mirroring and plain disk striping. - protects data and is fast. - has read performance increase you see with RAID 0, plus it includes fault tolerance without using as much disk space as RAID 1. - common in network servers.

parallel ATA (PATA)

- send data in parallel, on a wide 40- or 80- wire data cable. - the cable has an attenuation of 18 inches. - all use a std Molex power connector. - ancient ______ drives (33 MBps & slower) could get by w/a 40-pin ribbon cable. - Drives that go 66MBps or faster required an 80-wire cable. - you can connect up to two __________ drives including hard drives, optical drives, & tape drive to a single ATA controller. - Set jumpers on the drive to make one master and the other slave. - is a 16-bit parallel interface that has been almost completely phased out in favor of the serial interface of SATA.

Non-volatile Memory Express (NVMe)

- specification supports a communication connection b/w the OS and the SSD directly through a PCIe bus lane, reducing latency and taking full advantage of the wicked-fast speeds of high-end SSDs. designed to more fully utilize the parallelism built in to modern systems. - Supports up to 64K queues with up to 64K commands per queue. Allows for commands to be far more rapidly delivered to SSDs. - come in as add-on expansion cards & a 2.5-inch drive, like the SATA drives for portables. - these drives are more expensive but offer much higher speeds.

Disk Striping (RAID 0)

- spreading the data among multiple (at least two) drives. - Not fault tolerant - only advantage is speed. - if either drive fails, all data is lost. - provides no redundancy. - example is if you have a small Microsoft word file, the file is split into multiple pieces; half of the pieces go on one drive & half on the other. - Two or more (non-redundant) drives - Fast, but not really safe - Both drives are assigned the same drive letter.

RAID 0----Disk Striping

- takes the contents of files and spread them in roughly even parts across the hard drives in the RAID array. - Requires at least 2 drives. does not provide redundancy to data. - It does not include fault tolerance. - If one drive fails, all data is lost.

JBOD (Just a Bunch of Disks)

- term for a storage system composed of multiple independent disks of various sizes. - popular drive controllers support this.

Stacked memory

- the cutting-edge memory in SSDs are__________, which takes NAND & adds a third dimension to it, giving it increased density & capacity.

Solid-state drive (SSD)

- use memory chips to store data instead of moving parts. - they are based on the combination of semiconductors & transistors used to create electrical components w/no moving parts. - commonly used in desktop & laptop hard drives, memory cards, USB thumb drives, & other handheld devices. - More expensive than traditional HDDs.

Hardware RAID

- used when you need speed along with data redundancy. - need a controller. - provides hot-swapping.

Hot-swapping entails two elements:

1. The capacity to plug a device into the computer without harming either. 2. once the device is safely attached, it will be automatically recognized & become a fully functional component of the system.

* PATA * SATA * eSATA * USB for desktop systems * mini-PCIe for portable computers

SSDs can be: