Windows Server 2012 : Managing and Troubleshooting Hardware (part 1) - Understanding hardware installation changes

Understanding hardware installation changes

Hardware installation for Windows Server 2012 hasn’t changed much. What has changed significantly, however, are the available options when it comes to hardware devices. All computers can use internal and external hardware devices.

Choosing internal devices

Internal hardware devices are devices you install inside your computer. Typically, you’ll need to power down and unplug your computer, and then remove the computer case before you can install an internal device.

Hard drives are the most commonly installed internal devices and, in this area, there are many options. Windows Server 2012 supports both Standard Format and Advanced Format hard drives. Standard Format drives have 512 bytes per physical sector and are also referred to as 512b drives. Advanced Format drives have 4096 bytes per physical sector and are also referred to as 512e drives. 512e represents a significant shift for the hard drive industry, and it allows for large, multiterabyte drives.

Working with advanced-format hard drives

Hard drives perform physical media updates in the granularity of their physical sector size. 512b drives work with data 512 bytes at a time; 512e drives work with data 4096 bytes at a time. Having a larger physical sector size is what allows 512e drive capacities to jump well beyond previous physical capacity limits of 512b drives.

Keep in mind, however, that enterprise applications might need to be updated to work efficiently with 512e drives. When there is only a 512-byte write, hard disks must perform additional work to complete the 4096-byte sector write. For optimal performance, applications must read and write data properly in this new level of granularity (4096 bytes).

With 512b and 512e, it’s not an all-or-nothing proposition. Drive manufacturers have released drives with technology that allows them to transition from 512b to 512e. Seagate drives with SmartAlign technology are one example.

If you don’t know whether a drive is standard format or advanced format, you can easily determine bytes per physical sector by typing the following at an elevated command prompt:

Fsutil fsinfo ntfsinfo DriveDesignator

Here DriveDesignator is the designator of the drive to check, such as

Fsutil fsinfo sectorinfo c:

Small Computer System Interface (SCSI) is one of the most commonly used interfaces, and there are multiple bus designs for SCSI and multiple interface types. Parallel SCSI (also called SPI), though popular, is giving way to Serial Attached SCSI (SAS). Internet SCSI (iSCSI) uses the SCSI architectural model, but it uses TCP/IP as the transport rather than the traditional physical implementation.

Although many workgroup and enterprise-class server systems continue to use serial attached SCSI devices, servers aren’t always built using such robust disk systems. Increasingly, for general use, desktop-class computers are being configured with server operating systems, and most of these computers use internal devices with Serial ATA (SATA). That said, for many years, enhanced integrated drive electronics (EIDE), also called Parallel ATA (PATA), was used with desktop class computers.

Understanding solid-state drives

Solid-state drives (SSDs) are increasingly being used in computers throughout the enterprise. Although they can be higher in cost than traditional hard disks, they make up for this with high performance, reliability, and low power consumption. Because SSDs have no moving parts, they also run quiet and cool. How do they do this? SSDs use flash memory modules rather than platters, and there are no disk heads that need to travel over platters to read data. Instead, data is accessed directly from the flash memory over multiple internal flash buses. Typically, SSDs use NAND flash memory modules that have either multilevel cells (MLCs) storing two bits per cell or single-level cells (SLCs) storing one bit per cell.

In data centers where reducing power and cooling requirements is extremely important, you might want to use SSDs. Indeed, a typical SSD uses around 400 to 700 milliwatts of power and runs cool as opposed to the typical SCSI hard drive, which uses 4 to 7 watts of power and requires cooling. Before you deploy SSDs, however, keep in mind that a SATA SSD is not the same as a SATA hard drive. Most SSDs require specialized hard disk controllers to operate whether they are SATA compliant or not.

SSDs are ideal for high random read, low write workloads. For enterprise use, you should keep in mind that SSDs have duty-cycle and lifespan limitations. Check the warranty and specifications to determine an SSD’s specific duty-cycle and lifespan limitations. Duty-cycle limitations, often listed in Total Bytes Written or Bytes Per Day, directly affect how many times the flash memory can be written to. Lifespan limitations directly affect how long the SSD will be viable. Often SSDs are optimized for durability to extend their lifespan, but doing so might require significant overhead. As an example, one current enterprise SSD had a 7 percent provisioning overhead, meaning 7 percent of the raw drive capacity was reserved for code storage and wear leveling. With a 400-GB SSD, this means that approximately 28 GB of the raw capacity is dedicated to provisioning overhead, leaving 372 GB of raw capacity for data storage.

SATA was designed to replace IDE. SATA drives are increasingly popular as a low-cost alternative to SCSI. SATA II and SATA III, the most common SATA interfaces, are designed to operate at 3 gigabits per second and 6 gigabits per second, respectively. Windows Server 2012 provides improved support for SATA drives by reducing metadata inconsistencies and allowing SATA drives to cache data more efficiently. Improved disk caching helps to protect cached data in the event of an unexpected power loss.

Although Windows Server 2012 can be used with SCSI, EIDE, and SATA hardware devices, your computer must be configured specifically to work with these devices. For example, your computer needs a SCSI controller card to use SCSI devices. Although some older computer system motherboards don’t have SATA input ports, you can install a SATA controller card to add support for SATA drives.

Choosing external devices

External hardware devices are devices you connect to your computer. Because you don’t have to open your computer’s case to connect external devices, you typically don’t need to power down or unplug your computer before installing an external device. This makes external devices easier to install and also means you can attach most external devices without having to restart your computer.

Most current computers use external devices with USB, FireWire, external SATA (eSATA), or a combination of these interfaces. An example of each interface is shown in Figure 1.

Figure 1. Current interfaces for external devices.

USB 2.0 is the industry standard, while 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). High-speed USB 2.0 supports data transfers at a maximum rate of 480 megabits per second, with sustained data transfer rates usually from 10 to 30 megabits per second. The actual sustainable transfer rate depends on many factors, including the type of device, the data you are transferring, and the speed of your computer. Each USB controller on your computer has a fixed amount of bandwidth, which all devices attached to the controller must share. If your computer’s USB port is an earlier version, USB 1.0 or 1.1, you can use USB 2.0 and USB 3.0 devices, but the transfer rates will be significantly slower. The same is true when using a USB 2.0 device in a USB 3.0 port. Figure 2 compares connectors for USB 2.0 and USB 3.0.

Figure 2. Comparing USB 2.0 and USB 3.0 connectors.

Using USB 3.0

USB 3.0 has transfer rates up to 4.8 Gbps, which is 10 times faster than the maximum transfer rate of USB 2.0. To use USB 3.0, a computer must have USB 3.0–compliant ports and buses, and you must connect USB 3.0–compatible devices to computers using USB 3.0–compatible cables. Often, USB 3.0 ports and cables can be easily differentiated from USB 2.0 ports and cables. This is because USB 3.0 ports and cables normally have a blue color coding on the inside.

The blue coding is only one of several physical differences between USB 2.0 and USB 3.0 ports and cables. USB 2.0 cables have four wires within the cable and provide power up to 500 milliamps (mA). USB 3.0 cables have eight wires within the cable and provide power up to 900 mA. While USB 2.0 ports have four internal connectors, USB 3.0 ports have eight internal connectors.

Additionally, although USB 3.0 is capable of transfer rates up to 4.8 Gbps, the sustained data transfer rate is much lower. The bus type also might be a limiting factor because older buses might not be capable of reaching the maximum rate. For example, PCIe 1.0a and ExpressCard 1.0 buses have a maximum transfer rate of 2.5 Gbps.

TROUBLESHOOTING: Connecting USB 3.0 to USB 2.0 and vice versa

USB 3.0 cables and ports have different connectors than USB 2.0 cables and ports. To operate properly, USB 3.0 devices require USB 3.0 cables. USB 3.0 cables with standard connectors (A-type connectors), like the connector shown in Figure 1, can be used with USB 2.0 devices and plugged into USB 2.0 ports, but they are subject to the USB 2.0 transfer rate and power limitations. USB 2.0 devices and cables with standard connectors can be plugged into USB 3.0 ports and will work properly. USB 2.0 devices and cables with other connector types (B-type or micro B-type connectors) will not work properly with USB 3.0 ports. That said, although you might be able to fit a USB 2.0 cable with a B-type connector into a USB 3.0 B port, data will not transfer properly because of the different wiring configuration.

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 your computer. Generally speaking, never connect devices through a server’s monitor when end-user performance is a concern.

FireWire, also called IEEE 1394, is a high-performance connection standard for most Windows-based computers. This interface uses a peer-to-peer architecture in which peripherals negotiate bus conflicts to determine which device can best control a data transfer. FireWire has several configurations, including FireWire 400, FireWire 800, and FireWire 1600. 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.

eSATA is an ultra-high-performance connection standard, primarily used with high-performance external devices. With external hard drives, eSATA provides a secure, reliable, and ultra-fast connection. eSATA has maximum sustained transfer rates of up to 3 Gbps. Note that there are several types of eSATA connectors and cables, and that eSATA and internal SATA cables and connectors cannot be used interchangeably.

Using FireWire devices

Although Windows Server 2012 can be used with FireWire hardware devices, your computer must be configured specifically to work with these devices. Specifically, a computer needs a FireWire controller card.

When working with FireWire, keep in mind FireWire ports and cables have different shapes and connectors, making it easy to tell the difference between them—if you know what you’re looking for. Early FireWire implementations, which I’ll call standard FireWire (as opposed to FireWire 400 or FireWire 800), have a different number of pins on their connector cables and a different number of connectors on their ports. Because of this, you can tell standard FireWire and FireWire 400 apart by looking closely at the cables and ports.

If you look closely at standard FireWire cables and ports, you’ll see 4 pins or 4 connectors. If you look closely at FireWire 400 cables and ports, you’ll see 6 pins or 6 connectors. Although standard FireWire and FireWire 400 cables have rectangular-shaped connectors with one short flat end and the other rounded, FireWire 800 cables are square with one of the long sides having a notch.

When you are purchasing external devices, you might want to get a device with multiple interfaces. A device with multiple interfaces will give you more configuration options.