CompTIA A+ Core Certification: The Basics of IT Hardware Part 3 - Installing Storage Devices

220-1101: Objective 3.3: Given a scenario, select and install storage devices.
In this section, the focus is on hardware storage attached to the computer—specifically, optical storage, magnetic storage, and flash memory. Optical drives are not as prevalent as they once were, but they are still being used and are listed on the A+ objectives. Each type of storage can be a viable solution for a storage problem, and you should be able to discuss the differences among them.

Optical Drives
Optical drives fall into three major categories:
Drives based on CD technology, including CD-ROM, CD-R (recordable CD), and CD-RW (rewritable CD)
Drives based on DVD technology, including DVD-ROM, DVD-ROM/CD-RW combo, DVD-ROM/DVD-RW/DVD-RW DL, DVD-RAM, DVD-R/RW, DVD+R/RW, DVD± R/RW, and DVD± R/RW DL
Drives based on Blu-ray technology, including BD-ROM, Combo BD-ROM/DVD Super Multi, BD-R, and BD-RE

All three types of drives store data in a continuous spiral of indentations called pits and lands that are burned into the nonlabel side of the disc from the middle outward to the edge. All these drives use a laser to read the data.
The difference in the storage capacities of Blu-ray, DVD, and CD results from the differences in laser wavelengths. The shorter the wavelength, the smaller the pits and lands on the disc—and shorter wavelengths enable more data to be stored in the same space. Each type has a different capacity:
Blu-ray, which has the highest capacity, uses a blue laser with a shorter wavelength than DVD or CD.
DVD uses a red laser with a longer wavelength than Blu-ray but shorter than that of CD.
CD, which has the lowest capacity, uses a near-infrared laser with the longest wavelength.
Most CD, DVD, and Blu-ray drives are tray loading, but some use a slot-loading design (especially in home and automotive electronics products).

CD-ROM/CD-RW
CD-R and CD-RW drives use special media types and a more powerful laser than the one used on CD-ROM drives to write data to the media. CD-R is a “write-once” media type; that is, the media can be written to during multiple sessions, but older data cannot be deleted. CD-RW media can be rewritten up to 1,000 times. The 80-minute CD-R media has a capacity of 700MB, whereas the older 74-minute CD-R media has a capacity of 650MB. CD-RW media capacity is up to 700MB but is often less, depending on how the media is formatted. CD-RW media is available in four types:
CD-RW 1x–4x
High-speed CD-RW 4x–12x
Ultra-speed CD-RW 12x–24x
Ultra-speed+ CD-RW 32x
Drives compatible with faster media types can usually work with slower media types, but not the other way around.

DVD Recordable and Rewritable Standards
DVD-R and DVD+R media is recordable but not erasable, whereas DVD-RW and DVD+RW media use a phase-change medium similar to CD-RW and can be rewritten up to 1,000 times.
Consider these characteristics of the many members of the DVD family:
DVD-R: A single-sided, single-layer, writable/nonerasable medium similar to CD-R. Capacity of 4.7GB. Some DVD-RAM and all DVD-RW drives can use DVD-R media.
DVD-R DL: A single-side writable/nonerasable medium similar to CD-R, but with a second recording layer. Capacity of 8.4GB.
DVD-RW: A single-sided rewritable/erasable medium similar to CD-RW. Capacity of 4.7GB. DVD-RW drives can also write to DVD-R media.
DVD+RW: A rewritable/erasable medium. Also similar to CD-RW, but not interchangeable with DVD-RW or DVD-RAM. Capacity of 4.7GB.
DVD+R: A single-side, single-layer writable/nonerasable medium. Also similar to CD-R, but not interchangeable with DVD-R. Capacity of 4.7GB.
DVD+R DL: A writable/nonerasable medium with a second recording layer. Also similar to CD-R, but not interchangeable with DVD-R DL. Capacity of 8.4GB.
SuperMulti DVD drives can read and write all types of DVD media, as well as CD media. Sometimes these drives are also referred to as DVD± R/RW. Some early DVD+R/RW and DVD-R/RW drives cannot write to DL media.

Blu-ray Disc (BD)
Blu-ray disc (BD) technology is an enhancement of the DVD technology that offers greater storage capacity. It was developed by a consortium of electronics companies. BD drives are compatible with BD-ROM (read-only Blu-ray media), such as the media used for Blu-ray movies. To play back Blu-ray movies, you must have a compatible player app installed. Standard-capacity BD media types include the following:
BD-R: Recordable, not erasable. Similar to CD-R, DVD+R, DVD-R. 25GB capacity.
BD-R DL: Dual-layer recordable media. Similar to DVD+R DL, DVD-RW DL. 50GB capacity.
BD-RE: Recordable and rewritable. Similar to CD-RW, DVD-RW, DVD+RW. 25GB capacity.
BDXL: BDXL drives and media represent a large jump in capacity over standard BD drives and media. The BDXL specification was released in April 2010. It supports multilayer 100GB and 128GB recordable media (BD-R 3.0) and multilayer 100GB rewritable media (BD-RE Revision 4.0). Many, but not all, BD-RE compatible drives are compatible with BDXL standards. Check the drive’s specifications to determine compatibility.

Drive Speed Ratings
Drive speeds are measured by an X-rating:
CD media: 1X equals 150KB/s, the data transfer rate used for reading music CDs. Multiply the X-rating by 150 to determine the drive’s data rate for reading, writing, or rewriting CD media.
DVD media: 1X equals 1.385MB/s; this is the data transfer rate used for playing DVD-Video (DVD movies) content. Multiply the X-rating by 1.385 to determine the drive’s data rate for reading, writing, or rewriting DVD media.
Blu-ray Disc (BD) media: 1X equals 4.5MB/s; this is the data transfer rate for playing Blu-ray movies. Multiply the X-rating by 4.5 to determine the drive’s data rate for reading, writing, or rewriting Blu-ray media.
Blu-ray drives are also compatible with CD and DVD media. Check the specifications for a particular drive to determine the specific types of media it supports and the maximum read/write/rewrite speeds for each media type.

Recording Files to Optical Discs
You can use the following methods to record files onto optical discs:
Built-in recording features in Windows or other operating systems
Third-party disc mastering programs
Third-party drag-and-drop programs
All optical media must be formatted, but depending on how you write to the media, the formatting process might be incorporated into the writing process or might require a separate step. Because of digital rights management, significant differences exist between Windows 8 and 10 when writing copyright-protected files. Third-party software such as VLC is commonly used to play and manage media.

Hard Drives
Hard drives are the most important storage devices used by personal computers. A hard drive stores the operating system (Windows, macOS, Linux, or others) and loads it into the computer’s memory (RAM) at startup. Hard drives also store applications, system configuration files used by applications and the operating system, and data files created by the user.
Hard disk drives (HDDs) have traditionally been magnetic drives, but in recent years, solid-state drives (SDDs) and hybrid magnetic/SSD (SSHDs) have become viable options for storage. These are discussed in the sections that follow.

Solid-State Drive (SSD)
An SSD is a flash memory drive with no moving parts. Because the drive does not spin to retrieve data, it is much faster than a magnetic hard drive for storing and retrieving data. SSD is currently more expensive, with less capacity than HDD, but SSD capacity is improving and costs are dropping.
A typical SSD (see Figure) has a 2.5-inch form factor, but an optional 2.5-inch-to-3.5-inch adapter enables it to be installed in desktop computers that lack 2.5-inch drive bays. SSDs placed in drive bays are faster, but they still connect via the hard drive cables to connect to the motherboard.



An SSD with Optional Data Transfer Cable and 2.5-Inch-to-3.5-Inch Bay Adapter

A common upgrade to improve speed and capacity for a computer is to install an SSD to replace an older, slower, and smaller HDD. Because only newer motherboards and chipsets support M.2 drives (pronounced “M-dot-2”), adapting an SSD into a desktop is a common solution. (A good time to do this is when upgrading to Windows 10 or Windows 11 because loading the OS on the SSD makes the booting and updating processes much faster and avoids a cloning process to migrate the OS to the new drive.) Having the OS image copied to a USB flash drive makes installation easy.
M.2 is an SSD that can mount directly onto the motherboard or an expansion card, giving the drive more direct access to the CPU for much faster reading than is possible with an SSD. An M.2 has an appearance closer to that of a RAM chip than to that of a standard hard drive. A motherboard must be specifically designed to accept an M.2 SSD, so M.2s are not a likely option for a legacy system.
Although M.2 SSDs are currently more expensive, they have the potential to be both faster and lighter than standard SSDs. Depending on the motherboard and operating system, upgrading to either an SSD or an M.2 SSD (pictured later in this section, in Figure 3-32) is possible. The M.2 SSD requires an available PCIe slot. If the motherboard does not have a PCIe slot, a PCIe adapter can be purchased to enable the drive. In BIOS/UEFI, the M.2 drive can be enabled by locating the drive in the PCI drive settings.

The following steps describe how to install an SSD in a desktop with a new OS image:
Step 1. Be sure the desktop has room for another drive, a bay to hold the drive and a SATA connection on the motherboard, and a Molex cable to power the SSD. If you are replacing the hard drive, back up files first. 
Step 2. Gather a new SSD, adapter bracket, and, if necessary, SATA cable. The bracket screws are very small, so be sure to also have a quality small Phillips screwdriver. Follow the instructions to mount the SSD into the bracket.
Step 3. Mount the bracket into the spare drive bay. Attach the SATA cable from the SSD to the motherboard. Attach the Molex power connector to power the drive. Tuck away the cables, close up the box, and reconnect the external power.
Step 4. Boot the computer and enter the BIOS/UEFI settings to set the boot drive to the USB flash with the new OS. If you are installing Windows 10/11, when you see the prompt for choosing which drive for the installation, choose the new SSD drive. Let the install run.
Step 5. Upon reboot, enter the BIOS/UEFI and set the boot order to boot from the new SSD with the OS.

To perform this process in a laptop, you might need to visit the manufacturer support page to determine the best method to access the hard drive. The process is mostly the same, but on a smaller scale. Laptops do not have room for additional drives, so backing up to an external drive is necessary.

Figure below depicts the tight workspace encountered when removing a hard drive from a laptop.



Laptop HD Removal

SSDs are also available in these form factors:
mSATA (miniPCIe form factor): Used by some high-performance laptops and desktops.
M.2 (smaller than miniPCIe; pronounced “M-dot-2”): Faster than mSATA. Used in some high-performance desktops and laptops, but becoming increasingly popular as prices drop. Needs a specific form factor because it attaches directly to the motherboard.
PCIe card: For high-performance desktops. This is a way for SSDs to access the CPU by directly attaching to the motherboard and bypassing the traditional hard drive infrastructure.

An M.2 SSD



An M.2 SSD Installed in a High-Performance Desktop Computer

SSDs use one of two types of flash memory: multilevel cell (MLC) or single-level cell (SLC). MLC memory has lower performance than SLC and does not support as many write cycles, but it is much less expensive per gigabyte than SLC memory. Almost all SSDs sold in the consumer space use MLC flash memory. The differences in performance for similarly sized drives are based on the controller used, the firmware version in use, and whether the drive uses separate memory for caching or uses a portion of the SSD.
Although SSDs emulate hard disks, there are differences in their operation. Because unnecessary writing to flash memory causes premature failure, SSDs should not be defragmented. Newer SSDs use a feature known as TRIM to automatically reallocate space used by deleted files and make it available for reuse. TRIM is supported by modern Windows versions, but older SSDs require you to use vendor-supplied utilities to perform this task.
When Windows detects an SSD, it enables TRIM (if the drive supports this command), disables defragment, and disables other utilities, such as SuperFetch and ReadyBoost, that are designed for use with traditional hard disks.

SSHD
A solid-state hybrid drive (SSHD) combines a solid-state cache with magnetic capacity. It uses a memory manager to choose the most common files for the fast cache. An SSHD can be a good choice if improved performance and high capacity are desired, but the cost of large SSDs is prohibitive, especially in laptops that lack the capacity for multiple drives.

Table: Comparison of the Three Hard Drive Types

NVMe
One of the big reasons SSD is faster than HDD is the lack of moving parts. However, this benefit created another problem: With all the available capacity to access data, the SSDs still had to funnel all the data through a communication infrastructure designed for much slower HDDs. To solve this problem, a consortium of electronics companies pooled their resources to develop >Non-Volatile Memory Express (NVMe). NVMe is a protocol designed to allow SSDs to transfer data between the motherboard and the SSD at staggeringly higher rates. It involved redesigning the command queueing method AHCI to create NVMe.
NVMe is not a physical form factor like M.2, nor is it an interface like PCIe; in fact, both of these can use NVMe. It is a protocol (or set of communication rules) that allows SSD data to bypass the bottleneck that happens with HDD infrastructure. The older protocol Advanced Host Controller Interface (AHCI) uses a process called command queuing to send requested data to the controller and motherboard. It is capable of handling one command queue with 32 commands at a time. NVMe, in contrast, can process more than 65,000 queues at one time, with each queue containing up to 65,000 commands. Needless to say, such data rates are having a huge impact on the kinds of applications being designed.
For NVMe to work, the computer’s BIOS/UEFI and hardware needs to be designed for the high traffic, so only newer computers can physically support NVMe. On the software side, NVMe is supported by Windows, macOS, Linux, and Chrome OS.

SATA 2.5
SATA 2.5 refers to an HDD with a 2.5-inch form factor. These are usually found in laptops, and larger 3.5-inch HDDs are found in desktops. The 2.5 inches refers to the size of the spinning platters inside the HDDs. They are connected to the motherboard internally with a SATA cable.

PCIe
Peripheral Component Interconnect Express (PCIe) is a common expansion slot on a motherboard that provides peripheral devices such as SSDs and graphic processing units (GPUs) direct access to the CPU. This gives PCIe SSDs an edge over SATA SSDs because data does not need to go through RAM before reaching the CPU. This results in faster data transfer times compared to SATA SSDs.

Magnetic Hard Disk Drives
Traditional hard disk drives use one or more double-sided platters formed from rigid materials such as aluminum or glass. These platters are coated with a durable magnetic surface divided into sectors. Each sector contains 512 bytes of storage, along with information about where the sector is located on the disk medium. Sectors are organized in concentric circles, from the edge of the media inward toward the middle of the platter. These concentric circles are called tracks.
Hard disk drives are found in many desktop PCs; many newer PC systems and most newer mobile computers typically use some form of SSD.
External drives typically include SATA hard disks with a bridge controller for use with USB 2.0, USB 3.0, or USB4 ports. Drives made for macOS include USB or Thunderbolt ports. Some external drives can also connect to eSATA ports. External drives that use 3.5-inch desktop hard disks require AC power, but most external drives that use 2.5-inch or smaller mobile hard disks can be bus powered, receiving power from the USB port on the host computer.

Speeds/Spin Rate
The speed at which hard disk media turns, its spin rate, is measured in revolutions per minute (rpm). Hard drives have four common speeds:
Low-performance hard disks typically spin at 5400rpm.
Midperformance drives spin at 7200rpm.
High-performance desktop drives spin at 10000rpm.
Drives designed for use in enterprise computing, such as servers, spin at rates up to 15000rpm.
It is generally felt that the 15000rpm drives are being built mostly for existing system replacements because their speed comes with higher power use. SSDs are leaping forward in speed and capacity, with a fraction of the energy use of the 15000rpm drives.

Table: Hard Disk Spin Rate Comparison

*Actual spindle speed 5900RPM

Form Factors
Internal hard disk drives for desktop computers use 3.5-inch form factors. Their capacities range up to 8TB, but most installed desktop drives in recent systems have capacities ranging from 500GB to 2TB.
Internal hard disk drives or SSDs for laptop computers use the SATA 2.5-inch form factors. Their capacity ranges up to 3TB, but most laptop drives in recent systems have capacities ranging from 500GB to 1TB.
compares front and rear views of a DVD drive, 3.5-inch desktop hard disk, SATA 2.5-inch laptop hard disk, and 2.5-inch laptop SSD.



Front (Left) and Rear (Right) Internal Optical, Desktop, and Mobile Internal Hard Disks, and Mobile Internal SSD Drives


Cache Sizes and Performance
Aside from interface type and spin rate, the drive’s cache size also influences hard disk performance. In a hard disk, the cache is used to hold recently read information for reuse. As with processor cache memory, which often enables the CPU to read cache memory instead of the slower main memory to reuse previously read information, hard disks with larger buffers can reread recently transferred information more quickly from cache than from the drive’s magnetic storage.
In general, high-performance drives have larger caches than lower-performance drives. The larger-capacity drives in any given series typically have larger caches than the smallest-capacity drives in the same drive series.

Hybrid Drives
A hybrid drive combines a standard SATA hard disk with up to 8GB of the same type of solid-state (SS) memory used in SSDs. The SATA hard disk is used for most of the storage, but the recent files are kept in the SS cache for fast access. Just as in SSD drives, the SS memory provides much faster data access than do purely mechanical hard disk drives. Consequently, when information needed by the CPU is available in the hybrid drive’s flash memory, it is read from that memory, which boosts performance. Hybrid hard disk (also known as SSHD) drives are available in both 3.5-inch and 2.5-inch form factors. SSHDs are the middle ground in terms of cost and performance between HDDs and SSDs. Refer to Table 3-9 to review how SSHD compares to other drive types.

Flash Drives/Memory Cards
Flash memory is a type of memory that can retain its contents without electricity. It has no moving parts, so it is very durable. Standard flash memory is used in digital media players, memory cards for cameras and digital media devices, digital camcorders, and USB thumb drives.
SSDs and >flash drives are related, but they are not the same. SSD means solid-state drive, which defines the drive as having no moving parts. Flash is a type of memory that SSDs currently use. SSD flash also operates at a much higher level than the flash drives discussed here. (Refer to the earlier section “Solid-State Drive (SSD)” for information on SLC and MLC.)

The figure illustrates the most common types of flash memory cards.




Common Flash Memory Card Types


Table: Flash Memory Card Capacities and Uses

Original version up to 8GB; Mark 2 version up to 32GB

Flash Card Reader
A card reader enables flash memory cards to be used with a computer. Most card readers assign a separate drive letter to each slot.



An External Multislot Card Reader That Supports a Wide Variety of Flash Memory Cards and Connects to a USB 3.0 Port



An Internal Card Reader That Connects to an Unused USB 2.0 Port Header on the Motherboard


Do not confuse flash card readers with smart card readers. Smart card readers are used as part of a security system to read ID cards with embedded security.

NOTE: Some printers and multifunction devices also include card readers. Some card readers built into printers and multifunction devices are used only for printing, whereas others can be used to transfer files to and from the host computer.
When you insert a flash memory card containing files in Windows, Windows might display a simplified AutoPlay dialog box. If AutoPlay does not appear, open File Explorer and navigate to the appropriate drive letter to use the files on the card.




A Typical AutoPlay Menu Displayed by Windows When a Flash Memory Card Containing Files Is Inserted into a Card Reader


Storage Device Configurations
When adding or replacing a storage drive, it is necessary to optimize it for its intended purpose. A common reason for adding storage is to create a fault-tolerant set of drives that will protect data in case a drive fails. This section details the process of building data security into a system using RAID and hot-swappable drives.

RAID Types
Redundant Array of Independent (or Inexpensive) Disks (RAID) is a method for creating a faster or safer single logical hard disk drive from two or more physical drives. The most common RAID levels include the following:
RAID Level 0 (RAID 0): Two drives are treated as a single drive, and both drives are used to simultaneously store different portions of the same file. This method of data storage is called striping. Striping boosts performance, but if either drive fails, all data is lost. Do not use striping for data drives.
RAID Level 1 (RAID 1): Two drives are treated as mirrors of each other, and changes to the contents of one drive are immediately reflected on the other drive. This method of data storage is called >mirroring. Mirroring provides a built-in backup method and delivers faster read performance than a single drive. It is suitable for use with program and data drives.
RAID Level 5 (RAID 5): Three or more drives are treated as a logical array, and parity information (used to recover data in the event of a drive failure) is spread across all drives in the array. It is suitable for use with program and data drives.
RAID Level 1+0 (RAID 10): Four drives combine striping plus mirroring for extra speed plus better reliability. It is suitable for use with program and data drives. RAID 10 is a striped set of mirrors.
Most PCs with RAID support include support for Levels 0, 1, and 10. Some high-performance desktop systems also support RAID 5. Systems that lack the desired level of RAID support can use a RAID add-on card. Table 3-12 provides a quick comparison of these types of RAID arrays.

Table: Comparisons of Common RAID Levels

Creating a SATA RAID Array
The advent of SSDs has disrupted the normal acceptance of RAID as the most reliable backup method, but RAID is still in widespread use. Many argue that because SSDs are several times more reliable than HDDs, using an SSD with an HDD backup could be the more reliable and cost-effective option. This thinking will likely change again as SSD prices continue to fall while capacity improves.
That said, here are the basics of setting up RAID on a PC.
Many recent desktop systems include SATA RAID host adapters on the motherboard. SATA RAID host adapter cards can also be retrofitted to systems that lack onboard RAID support. These types of RAID arrays are also referred to as hardware RAID arrays. RAID arrays can also be created through operating system settings and are sometimes called software RAID arrays. However, software RAID arrays are not as fast as hardware RAID arrays.
Motherboards that support only two drives in a RAID array support only RAID 0 and RAID 1. Motherboards that support more than two drives can also support RAID Level 1+0 (also known as RAID 10), and some support RAID 5 as well. RAID-enabled host adapters support varying levels of RAID.
A nonstandard definition of “RAID 10” was created for the Linux MD driver; Linux RAID 10 can be implemented with as few as two disks. Implementations supporting two disks, such as Linux RAID 10, offer a choice of layouts. Arrays of more than four disks are also possible.
A SATA RAID array requires the following:
Two or more drives: It’s best to use identical drives (with the same capacity, buffer size, and RPMs). However, you can mix and match drives. If some drives are larger than others, the additional capacity will be ignored. You can use standard hard disk drives, hybrid hard disks, or SSDs.
A RAID-compatible motherboard or add-on host adapter card: Both feature firmware that supports RAID.
Because RAID arrays typically involve off-the-shelf drives, the only difference in the physical installation of drives in a RAID array is where they are connected. They must be connected to a motherboard or an add-on card that has RAID support.
Sometimes RAID connectors are made from a different color of plastic than other drive connectors. However, the best way to determine whether a system or motherboard supports SATA RAID arrays is to read the manual for the system or motherboard.
When the drives used to create the array are connected to the RAID array’s host adapter, restart the computer. If you are using the motherboard’s RAID interface, start the system BIOS/UEFI setup program and make sure the RAID function is enabled (see Figure). Save the changes and exit the BIOS/UEFI setup program.



Enabling SATA RAID in a Typical System BIOS


When you restart the computer, watch for a prompt from the RAID BIOS to start the configuration process (see Figure).


A Typical Prompt to Start RAID Array Setup


Specify the desired RAID setting and any optional settings that you want to use. After the RAID array is configured, the system handles the drives as a single physical drive. If drivers for the array are not already installed, you need to install them when prompted by the computer. For Windows, you can provide driver files via USB or on optical discs, if necessary.



Preparing to Create a RAID 1 Array


If one or more of the drives to be used in the array already contains data, back up the drives before you start the configuration process. Most RAID array host adapters delete the data on all drives in the array when creating an array—sometimes with little warning.
If you do not have RAID adapters in a system, you can create a software RAID volume, also known as a disk array, by using Windows.
Some hard disk drive vendors now produce drives especially made for SOHO RAID arrays of eight or fewer drives. Compared to normal SATA hard disk drives, RAID-optimized drives (also known as NAS drives) typically include features such as vibration reduction, optimization for streaming, disabled head parking, intelligent recovery from errors, and longer warranties.

To add a RAID array to a laptop, convertible (two-in-one), or all-in-one PC, use an external RAID drive or drive enclosure that connects to a USB 3.0 (or greater), Thunderbolt, or eSATA port. An external RAID drive contains two hard disks that can be configured as RAID 0 or RAID 1. Enclosures with support for three or more drives can also be configured as RAID 5. Enclosures with support for four drives can be configured as RAID 10. Use the program provided with the drive or enclosure to configure the RAID array.

Hot-Swappable Drives
Hot-swappable drives are drives that can be safely removed from a system or connected to a system without shutting down the system. In Windows, the following drives can be hot-swapped:
USB drives
eSATA drives
SATA drives
Flash memory drives
eSATA and SATA drives must be configured as AHCI in the system BIOS/ UEFI firmware.
In most enterprise systems, the RAID drives are hot swappable.

Safely Ejecting a Drive in Windows
To safely eject a hot-swappable drive from a Windows system, follow these steps:

Step 1. Open the Eject/Safely Remove Hardware and Eject Media icon in the notification area. If the icon is not visible, click the up arrow to display hidden icons.
Step 2. Select the drive to eject from the menu.
Step 3. When the Safe to Remove Hardware message appears, disconnect the drive.




Safely Ejecting a Hot-Swappable Drive from a System Running Windows 10


If the drive is still in use, a Problem Ejecting type Storage Device dialog box appears, informing you that the drive is in use. Click OK, make sure no apps or processes are using the drive, and then try the process again.

Safely Ejecting a USB Drive in macOS
To safely eject a USB drive in macOS, follow these steps:
Step 1. Open Finder.
Step 2. Click the up arrow next to the USB drive icon in the left pane.
Step 3. When the drive icon is removed from the left pane of Finder, disconnect the drive.



Safely Ejecting a Hot-Swappable Drive from a macOS System


Safely Ejecting a USB Drive in Linux
Some Linux distributions include support for safely ejecting a USB drive. However, the terminal command df can be used to list mounted devices. If the USB drive is not listed as mounted, it can be removed immediately. If the USB drive is listed as mounted, you can use the following command:
sudo unmount /dev/sdb1 (where sbd1 is the mounted USB drive)
When the drive access light goes out, disconnect the drive.