Книга: Windows Server 2012 R2 Storage, Security, & Networking Pocket Consultant

Using removable storage devices

Using removable storage devices

Removable storage devices can be formatted with ReFS, NTFS, FAT, FAT32, or exFAT. You connect external storage devices to a computer rather than installing them inside the computer. This makes external storage devices easier and faster to install than most fixed disk drives. Most external storage devices have either a USB or a FireWire interface. When working with USB and FireWire, the transfer speed and overall performance of the device from a user’s perspective depends primarily on the version supported. Currently, several versions of USB and FireWire are used.

USB 2.0 is the current industry standard until the world transitions to USB 3.0. USB 2.0 devices can be rated as either full speed (up to 12 Mbps) or high speed (up to 480 Mbps). Although high-speed USB 2.0 supports data transfers at a maximum rate of 480 Mbps, sustained data-transfer rates are usually 10–30 Mbps. The actual sustainable transfer rate depends on many factors, including the type of device, the data you are transferring, and the speed of a computer. Each USB controller on a computer has a fixed amount of bandwidth, which all devices attached to the controller must share. The data transfer rates are significantly slower if a computer’s USB port is an earlier version than the device you are using. For example, if you connect a USB 3.0 device to a USB 2.0 port or vice versa, the device operates at the significantly reduced USB 2.0 transfer speed.

USB 1.0, 1.1, and 2.0 ports all look alike; however, most USB 3.0 ports I’ve seen have a special color to differentiate them. Still, the best way to determine which type of USB ports a computer has is to refer to the documentation that comes with the computer. Newer monitors have USB 2.0 ports to which you can connect devices as well. When you have USB devices connected to a monitor, the monitor acts like a USB hub device. As with any USB hub device, all devices attached to the hub share the same bandwidth, and the total available bandwidth is determined by the speed of the USB input to which the hub is connected on a computer.

FireWire (IEEE 1394) is a high-performance connection standard that uses a peerto-peer architecture in which peripherals negotiate bus conflicts to determine which device can best control a data transfer. Like USB, several versions of FireWire are currently used. FireWire 400 (IEEE 1394a) has maximum sustained transfer rates of up to 400 Mbps. IEEE 1394b allows 400 Mbps (S400), 800 Mbps (S800), and 1600 Mbps (S1600). As with USB devices, if you connect an IEEE 1394b device to an IEEE 1394a port or vice versa, the device operates at the significantly reduced FireWire 400 transfer speed.

As with USB ports, the sustained transfer rate for IEEE 1394a and IEEE 1394b ports will be considerably less than the maximum rate possible. IEEE 1394a and IEEE 1394b ports and cables have different shapes, making it easier to tell the difference between them-if you know what you’re looking for. FireWire 400 cables without bus power have four pins and four connectors. FireWire 400 cables with bus power have six pins and six connectors. FireWire 800 and FireWire 1600 cables always have bus power and have nine pins and nine connectors.

Another option is external SATA (eSATA), which is available on newer computers and is an ultra-high-performance connection for data transfer to and from external mass storage devices. eSATA operates at speeds up to 6 Gbps. If your computer doesn’t come with eSATA ports, you can add support for eSATA devices by installing an eSATA controller card.

When you are purchasing an external device for a computer, you’ll also want to consider what interfaces it supports. In some cases, you might be able to get a device with more than one interface, such as one that supports USB 3.0 and eSATA. A device with multiple interfaces gives you more options.

Working with removable disks is similar to working with fixed disks. You can do the following:

? Press and hold or right-click a removable disk, and then select Open or Explore to examine the disk’s contents in File Explorer.

? Press and hold or right-click a removable disk, and then select Format to format a removable disk as discussed in “Formatting partitions” later in this chapter. Removable disks generally are formatted with a single partition.

? Press and hold or right-click a removable disk, and then select Properties to view or set properties. On the General tab of the Properties dialog box, you can set the volume label as discussed in “Changing or deleting the volume label” in Chapter 2.

When you work with removable disks, you can customize disk and folder views. To do this, press and hold or right-click the disk or folder, select Properties, and then tap or click the Customize tab. You can then specify the default folder type to control the default details displayed. For example, you can set the default folder type as Documents or Pictures And Videos. You can also set folder pictures and folder icons.

Removable disks support network file and folder sharing. You configure sharing on removable disks in the same way you configure standard file sharing. You can assign share permissions, configure caching options for offline file use, and limit the number of simultaneous users. You can share an entire removable disk as well as individual folders stored on the removable disk. You can also create multiple share instances.

Removable disks differ from standard NTFS sharing in that they don’t necessarily have an underlying security architecture. With exFAT, FAT, or FAT32, folders and files stored on a removable disk do not have any security permissions or features other than the basic read-only or hidden attribute flags that you can set.

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