Problems with Computer Hard Disk Drive
Frustrated regarding data loss due to problems with Computer Hard Disk Drive? This is the biggest issue ever and here are some common problems and their simple but logical solutions.
Hard Disk Drive Common Problems and Best Solutions- an overview
Hard Disk Drive (HDD) is a non-volatile data storage device of a computer. Non-volatile refers to storage devices that preserve stored data when turned off. All computers need a storage device, and HDDs are one type of storage device among many.
HDDs are usually installed inside desktop computers, laptops, mobile devices, consumer electronics and enterprise storage arrays in data centers. They can store operating systems, software programs and other files using magnetic disks.
More specifically, hard disk drives control the reading and writing of the hard disk that provides data storage. HDDs are used either as the primary or secondary storage device in a computer. They are commonly found in the drive bay and are connected to the motherboard via an Advanced Technology Attachment (ATA), Serial ATA, parallel ATA or Small Computer System Interface (SCSI) cable, among other formats. The HDD is also connected to a power supply unit and can keep stored data while powered down.
Necessity of hard disks
Storage devices like hard disks are needed to install operating systems, programs and additional storage devices, and to save documents. Without devices like HDDs that can retain data after they have been turned off, computer users would not be able to store programs or save files or documents to their computers. This is why every computer needs at least one storage device to permanently hold data as long as it is needed.
Hard disk drives- functions
Most basic hard drives consist of several disk platters — a circular disk made of either aluminum, glass or ceramic — that are positioned around a spindle inside a sealed chamber. The platter spins with a motor that is connected to the spindle. The chamber also includes the read/write heads that magnetically record information to and from tracks on the platters using a magnetic head. The disks also have a thin magnetic coating on them.
The motor spins the platters at up to 15,000 rotations per minute. As the platters spin, a second motor controls the position of the read and write heads that magnetically write and read information on each platter.
Hard disk drive storage capacity
Some of the most common storage drive capacities include the following:
- 16 GB, 32 GB and 64 GB. This range is among the lowest for HDD storage space and is typically found in older and smaller devices.
- 120 GB and 256 GB. This range is generally considered an entry point for HDD devices such as laptops or computers.
- 500 GB, 1 TB and 2 TB. Around 500 GB and above of HDD storage is typically considered decent for an average user. Users can most likely store all their music, photos, videos and other files with this much space. Individuals with games that take up a lot of space should find 1 TB to 2 TB of HDD space suitable.
- More than 2 TB. Anything over 2 TB of HDD space is suitable for users who work with high-resolution image files, Video editing, animation and who need to store or house a large amount of data, or who want to use that space for backup and redundancy.
Currently, the highest capacity HDD is 20 TB. However, an HDD actually has less space than advertised, as the operating system, file system structures and some data redundancy procedures use a portion of that space, commonly known as swap file/system reserved.
Hard drive components and form factors
Hard disk drive components include the spindle, disk platter, actuator, actuator arm and read/write head. Even though the term can refer to the unit as a whole, the term hard disk is the set of stacked disks — in other words, the part of the HDD that stores and provides access to data on an electromagnetically charged surface.
The HDD form factor refers to the physical size or geometry of the data storage device. HDD form factors follow a set of industry standards that govern their length, width and height, as well as the position and orientation of the host interface connector. Having an industry-standard form factor helps determine a common compatibility with different computing devices.
The most common form factors for HDDs in enterprise systems are 2.5-inch and 3.5-inch — also known as small form factor (SFF) and large form factor (LFF). The 2.5-inch and 3.5-inch measurements represent the approximate diameter of the platter within the drive enclosures.
While there are other form factors, by 2009, manufacturers discontinued the development of products with 1.3-inch, 1-inch and 0.85-inch form factors. The falling price of flash drive made these other form factors almost obsolete. It is also important to note that while nominal sizes are in inches, actual dimensions are specified in millimeters.
Many solid-state drives (SSDs) are also designed for the HDD form factor. SSDs that fit into the same slots as HDDs generally use the SATA or serial-attached SCSI (SAS) interface to transfer data to and from the host computing system.
External HDDs
Most HDDs are found internally in a computer and work as stated above. However, individuals can also purchase external hard drives. External hard drives can be used to expand the storage capacity of a computer or to act as a portable device to back up data. External drives connect to a computer or device through interfaces like USB 2.0, USB-C or with External SATA (e-SATA). External hard drives may also have slower data transfer rates compared to internal HDDs.
The main advantage of an external hard drive, aside from being able to expand a device’s storage space, includes being portable. Users can store data from multiple devices and physically bring that data with them wherever they go.
History of hard disk drives
The hard disk was created in 1953 by engineers at IBM who wanted to find a way to provide random access to high capacities of data at a low cost. The disk drives developed were the size of refrigerators, could store 3.75 MB of data and began shipping in 1956. Memorex, Seagate Technology and Western Digital were other early vendors of hard disk drive technology.
Hard disk drive form-factor size has continued to decrease as the technology evolves. By the mid-1980s, 3.5-inch and 2.5-inch form factors were introduced and became a standard in personal computers.
Hard disk drive density has increased since the technology was first developed. The first hard disk drives could store megabytes of data, while today their storage capacity is in the terabyte range. Hitachi Global Storage Technologies (HGST) — now a Western Digital brand — released the first 1 TB hard drives in 2007. In 2015, HGST announced the first 10 TB hard drive. And in 2021, Western Digital unveiled two 20 TB HDDs.
HDD evolution and technology developments
In 2013, Seagate Technology announced hard disk drives that use shingled magnetic recording (SMR) technology. SMR increases storage density in hard disk drives by layering the magnetic tracks on each disk, rather than placing them parallel to each other. It is referred to as shingled because the tracks overlap similar to shingles on a roof.
HGST announced the first helium-filled hard disk drive in 2012. Helium is less dense, cooler and lighter than air, consumes less power, increases drive density and improves performance compared to traditional hard disk drives. In 2016, Seagate announced its first 10 TB helium hard drive.
In 2021, drive manufacturer Western Digital unveiled two 20 TB HDDs — the Ultrastar DC HC560 and WD Gold HDD Enterprise Class SATA HDD. Currently, 20 TB is the largest available HDD size. Both hard disk drives come in the standard 3.5-inch form factor but have different use cases. The Ultrastar DC HC560 is meant for cloud storage providers and for business servers, security systems and network-attached storage devices. The WD Gold HDD is designed for enterprise businesses that run heavy application workloads.
HDDs vs. SSDs
The main alternative to hard disk drives are solid-state drives.
Unlike hard disks, SSDs contain no moving parts. SSDs also have lower latency than HDDs, and therefore are often favored to store critical data that needs to be accessed quickly and for applications with a high input/output demand. SSDs are configured to deliver high read/write speeds for sequential and random data requests. Additionally, SSDs do not store data magnetically, so the read performance remains steady, regardless of where the data is stored on the drive. SSDs also have faster boot times.
It is because of these benefits, and that HDDs are more vulnerable to breakdowns, that HDDs are now starting to be replaced by SSDs.
However, even though most PC users have started to favor SSDs, HDDs — along with magnetic tape — are still used frequently to store large amounts of data. In part, this is because SSDs are more expensive than HDDs from a price-per-gigabyte standpoint. Many enterprise storage arrays ship with a mix of HDDs and SSDs to reduce costs while providing better performance. SSDs also have a set life expectancy, with a finite number of write cycles before its performance slows down. Compared to an HDD, SSDs collapse faster.
The two most common form factors for modern HDDs are 3.5-inch, for desktop computers, and 2.5-inch, primarily for laptops. HDDs are connected to systems by standard interface cables such as PATA (Parallel ATA), SATA (Serial ATA), USB or SAS (Serial Attached SCSI) cables.
| Parameter | Started with (1957) | Improved to | Improvement |
| Capacity (formatted) |
3.75 megabytes | 18 terabytes
(as of 2020) |
4.8-million-to-one |
| Physical volume | 68 cubic feet (1.9 m3) | 2.1 cubic inches (34 cm3) | 56,000-to-one |
| Weight | 2,000 pounds (910 kg) |
2.2 ounces (62 g) |
15,000-to-one |
| Average access time | approx. 600 milliseconds | 2.5 ms to 10 ms; RW RAM dependent | about 200-to-one |
| Price | US$9,200 per megabyte (1961; US$83,107 in 2021) | US$0.024 per gigabyte by 2020 | 3.46-billion-to-one |
| Data density | 2,000 bits per square inch | 1.3 terabits per square inch in 2015 | 650-million-to-one |
| Average lifespan | c. 2000 hrs MTBF | 2,500,000 hrs (~285 years) MTBF | 1250-to-one |
Magnetic recording
A modern HDD records data by magnetizing a thin film of ferromagnetic material on both sides of a disk. Sequential changes in the direction of magnetization represent binary data bits. The data is read from the disk by detecting the transitions in magnetization. User data is encoded using an encoding scheme, such as run-length limited encoding, which determines how the data is represented by the magnetic transitions.
A typical HDD design consists of a spindle that holds flat circular disks, called platters, which hold the recorded data. The platters are made from a non-magnetic material, usually aluminum alloy, glass, or ceramic. They are coated with a shallow layer of magnetic material typically 10–20 nm in depth, with an outer layer of carbon for protection. For reference, a standard piece of copy paper is 0.07–0.18 mm (70,000–180,000 nm) thick.
Destroyed hard disk, glass platter visible
Recording of single magnetizations of bits on a 200 MB HDD-platter (recording made visible using CMOS-MagView).
The platters in contemporary HDDs are spun at speeds varying from 4,200 RPM in energy-efficient portable devices, to 15,000 rpm for high-performance servers. The first HDDs spun at 1,200 rpm and, for many years, 3,600 rpm was the norm. As of November 2019, the platters in most consumer-grade HDDs spin at 5,400 or 7,200 RPM.
Information is written to and read from a platter as it rotates past devices called read-and-write heads that are positioned to operate very close to the magnetic surface, with their flying height often in the range of tens of nanometers. The read-and-write head is used to detect and modify the magnetization of the material passing immediately under it.
In modern drives, there is one head for each magnetic platter surface on the spindle, mounted on a common arm. An actuator arm (or access arm) moves the heads on an arc (roughly radically) across the platters as they spin, allowing each head to access almost the entire surface of the platter as it spins. The arm is moved using a voice coil actuator or in some older designs a stepper motor. Early hard disk drives wrote data at some constant bits per second, resulting in all tracks having the same amount of data per track but modern drives (since the 1990s) use zone bit recording – increasing the write speed from inner to outer zone and thereby storing more data per track in the outer zones.
In modern drives, the small size of the magnetic regions creates the danger that their magnetic state might be lost because of thermal effects — thermally induced magnetic instability which is commonly known as the “super paramagnetic limit”. To counter this, the platters are coated with two parallel magnetic layers, separated by a three-atom layer of the non-magnetic element ruthenium, and the two layers are magnetized in opposite orientation, thus reinforcing each other. Another technology used to overcome thermal effects to allow greater recording densities is perpendicular recording, first shipped in 2005, and as of 2007 used in certain HDDs.
In 2004, a higher-density recording media was introduced, consisting of coupled soft and hard magnetic layers. So-called exchange spring media magnetic storage technology, also known as exchange coupled composite media, allows good writability due to the write-assist nature of the soft layer. However, the thermal stability is determined only by the hardest layer and not influenced by the soft layer.
Capacity
Two Seagate Barracuda drives, from 2003 and 2009 – respectively 160GB and 1TB. As of 2022 Seagate offers capacities up to 20TB.
The highest-capacity HDDs shipping commercially in 2022 are 20 TB.
The capacity of a hard disk drive, as reported by an operating system to the end user, is smaller than the amount stated by the manufacturer for several reasons: the operating system using some space, use of some space for data redundancy, and space use for file system structures. Also the difference in capacity reported in SI decimal prefixed units vs. binary prefixes can lead to a false impression of missing capacity.
Formatting
Data is stored on a hard drive in a series of logical blocks. Each block is delimited by markers identifying its start and end, error detecting and correcting information, and space between blocks to allow for minor timing variations. These blocks often contained 512 bytes of usable data, but other sizes have been used. As drive density increased, an initiative known as Advanced Format extended the block size to 4096 bytes of usable data, with a resulting significant reduction in the amount of disk space used for block headers, error checking data, and spacing.
The process of initializing these logical blocks on the physical disk platters is called low-level formatting, which is usually performed at the factory and is not normally changed in the field. High-level formatting writes data structures used by the operating system to organize data files on the disk. This includes writing partition and file system structures into selected logical blocks. For example, some of the disk space will be used to hold a directory of disk file names and a list of logical blocks associated with a particular file.
Examples of partition mapping scheme include Master boot record (MBR) and GUID Partition Table (GPT). Examples of data structures stored on disk to retrieve files include the File Allocation Table (FAT) in the DOS file system and inodes in many UNIX file systems, as well as other operating system data structures (also known as metadata). As a consequence, not all the space on an HDD is available for user files, but this system overhead is usually small compared with user data.
In the early days of computing the total capacity of HDDs was specified in 7 to 9 decimal digits frequently truncated with the idiom millions. By the 1970s, the total capacity of HDDs was given by manufacturers using SI decimal prefixes such as megabytes (1 MB = 1,000,000 bytes), gigabytes (1 GB = 1,000,000,000 bytes) and terabytes (1 TB = 1,000,000,000,000 bytes). However, capacities of memory are usually quoted using a binary interpretation of the prefixes, i.e. using powers of 1024 instead of 1000.
Software reports hard disk drive or memory capacity in different forms using either decimal or binary prefixes. The Microsoft Windows family of operating systems uses the binary convention when reporting storage capacity, so an HDD offered by its manufacturer as a 1 TB drive is reported by these operating systems as a 931 GB HDD. Mac OS X 10.6 (“Snow Leopard”) uses decimal convention when reporting HDD capacity. The default behavior of the command-line utility on Linux is to report the HDD capacity as a number of 1024-byte units.
The difference between the decimal and binary prefix interpretation caused some consumer confusion and led to class action suits against HDD manufacturers. The plaintiffs argued that the use of decimal prefixes effectively misled consumers while the defendants denied any wrongdoing or liability, asserting that their marketing and advertising complied in all respects with the law and that no class member sustained any damages or injuries.
Performance characteristics
The factors that limit the time to access the data on an HDD are mostly related to the mechanical nature of the rotating disks and moving heads, including:
- Seek time is a measure of how long it takes the head assembly to travel to the track of the disk that contains data.
- Rotational latency is incurred because the desired disk sector may not be directly under the head when data transfer is requested. Average rotational latency is shown in the table, based on the statistical relation that the average latency is one-half the rotational period.
- The bit rate or data transfer rate (once the head is in the right position) creates delay which is a function of the number of blocks transferred; typically relatively small, but can be quite long with the transfer of large contiguous files.
Delay may also occur if the drive disks are stopped to save energy.
Defragmentation is a procedure used to minimize delay in retrieving data by moving related items to physically proximate areas on the disk. Some computer operating systems perform defragmentation automatically. Although automatic defragmentation is intended to reduce access delays, performance will be temporarily reduced while the procedure is in progress.
Time to access data can be improved by increasing rotational speed (thus reducing latency) or by reducing the time spent seeking. Increasing areal density increases throughput by increasing data rate and by increasing the amount of data under a set of heads, thereby potentially reducing seek activity for a given amount of data. The time to access data has not kept up with throughput increases, which themselves have not kept up with growth in bit density and storage capacity.
Latency
| Latency characteristics typical of HDDs | |
| Rotational speed [rpm] |
Average rotational latency [ms] |
| 15,000 | 2 |
| 10,000 | 3 |
| 7,200 | 4.16 |
| 5,400 | 5.55 |
| 4,800 | 6.25 |
Data transfer rate
As of 2010, a typical 7,200-rpm desktop HDD has a sustained “disk-to-buffer” data transfer rate up to 1,030 Mbit/s. This rate depends on the track location; the rate is higher for data on the outer tracks (where there are more data sectors per rotation) and lower toward the inner tracks (where there are fewer data sectors per rotation); and is generally somewhat higher for 10,000-rpm drives.
A current widely used standard for the “buffer-to-computer” interface is 3.0 Gigabit/s SATA, which can send about 300 megabyte/s (10-bit encoding) from the buffer to the computer, and thus is still comfortably ahead of today’s disk-to-buffer transfer rates. Data transfer rate (read/write) can be measured by writing a large file to disk using special file generator tools, then reading back the file. Transfer rate can be influenced by file system fragmentation and the layout of the files.
HDD data transfer rate depends upon the rotational speed of the platters and the data recording density. Because heat and vibration limit rotational speed, advancing density becomes the main method to improve sequential transfer rates. Higher speeds require a more powerful spindle motor, which creates more heat. While areal density advances by increasing both the number of tracks across the disk and the number of sectors per track, only the latter increases the data transfer rate for a given rpm. Since data transfer rate performance tracks only one of the two components of areal density, its performance improves at a lower rate.
Modern interfaces connect the drive to the host interface with a single data/control cable. Each drive also has an additional power cable, usually direct to the power supply unit. Older interfaces had separate cables for data signals and for drive control signals.
Close-up of an HDD head resting on a disk platter; its mirror reflection is visible on the platter surface. Unless the head is on a landing zone, the heads touching the platters while in operation can be catastrophic.
Due to the extremely close spacing between the heads and the disk surface, HDDs are vulnerable to being damaged by a head crash – a failure of the disk in which the head scrapes across the platter surface, often grinding away the thin magnetic film and causing data loss.
Head crashes can be caused by electronic failure, a sudden power failure, physical shock, contamination of the drive’s internal enclosure, wear and tear, corrosion, or poorly manufactured platters and heads.
The HDD’s spindle system relies on air density inside the disk enclosure to support the heads at their proper flying height while the disk rotates. HDDs require a certain range of air densities to operate properly. The connection to the external environment and density occurs through a small hole in the enclosure (about 0.5 mm in breadth), usually with a filter on the inside (the breather filter).
If the air density is too low, then there is not enough lift for the flying head, so the head gets too close to the disk, and there is a risk of head crashes and data loss. Specially manufactured sealed and pressurized disks are needed for reliable high-altitude operation, above about 3,000 m (9,800 ft).
Modern disks include temperature sensors and adjust their operation to the operating environment. Breather holes can be seen on all disk drives – they usually have a sticker next to them, warning the user not to cover the holes. The air inside the operating drive is constantly moving too, being swept in motion by friction with the spinning platters.
This air passes through an internal recirculation filter to remove any leftover contaminants from manufacture, any particles or chemicals that may have somehow entered the enclosure, and any particles or external thing generated internally in normal operation.
Very high humidity present for extended periods of time can corrode the heads and platters. An exception to this are hermetically sealed, helium filled HDDs that largely eliminate environmental issues that can arise due to humidity or atmospheric pressure changes. Such HDDs were introduced by HGST in their first successful high volume implementation in 2013.
Hard Disk Drive Common Problems and Best Solutions 2022
Hard disks can fail for all sorts of reasons. However, failures generally fall into the following six broad categories.
- Electrical failure occurs when, for example, a power surge damages a hard disk’s electronic circuitry, causing the read/write head or circuit board to fail. If a hard disk powers on but cannot read and write data or boot, it is likely that one or more of its components has suffered an electrical failure.
- Mechanical failure can be caused by wear and tear, as well as by a hard impact, like a hard drop. This may cause, among other things, the read/write drive head to hit a rotating platter, causing irreversible physical damage.
- Logical failure results when the hard disk’s software is compromised or ceases to run properly. All sorts of data corruption can lead to a logical failure. This includes corrupted files, malware and viruses, improperly closing an application or shutting down a computer, human error or accidentally deleting files that are critical to hard disk functionality.
- Bad sector failure can occur when the magnetic media on a hard disk’s rotating platter is misaligned, resulting in a specific area on the platter becoming inaccessible. Bad sectors are common and often limited when they occur. Over time, however, the number of bad sectors can increase, eventually leading to a system crash, inaccessible files or the hanging or lagging of the operation of a hard disk.
- Firmware failure happens when the software that performs the maintenance tasks on a drive and enables the hard disk to communicate with a computer becomes corrupted or stops working properly. This type of failure can lead to the disk freezing during boot-up or the computer a hard disk is connected to not recognizing or misidentifying it.
- Other un-recognized failures that accumulate over time can also occur. For example, an electrical problem could lead to a mechanical failure, such as a read/write head crash. It might also lead to a logical failure, resulting in several bad sectors developing on the hard disk platters.
- Sometimes, due to faulty Power Supply Unit PATA or SATA cable, hard disk may crash. This usually happens when the hard disk does not get the required power for operation. The data cable may also generate problem, if it is less capable or of low quality. Always try to use the cables that came with your mother board to avoid crash.
