Adding Hard Disk Drives
Before you make a hard disk drive available to users, you'll need to configure it and consider how it'll be used. With Microsoft Windows Server 2008, you can configure hard disk drives in a variety of ways. The technique you choose depends primarily on the type of data you're working with and the needs of your network environment. For general user data stored on workstations, you might want to configure individual drives as stand-alone storage devices. In that case, user data is stored on a workstation's hard disk drive, where it can be accessed and stored locally.
Although storing data on a single drive is convenient, it isn't the most reliable way to store data. To improve reliability and performance, you might want a set of drives to work together. Windows Server 2008 supports drive sets and arrays using redundant array of independent disks (RAID) technology, which is built into the operating system.
Whether you use individual drives or drive sets, you'll need physical drives. Physical drives are the actual hardware devices that are used to store data. The amount of data a drive can store depends on its size and whether it uses compression. Typical drives have capacities of 100 gigabytes (GB) to 500 GB. Many drive types are available for use with Windows Server 2008, including Small Computer System Interface (SCSI), Parallel ATA (PATA), and Serial ATA (SATA).
The terms SCSI, PATA, and SATA designate the interface type used by the hard disk drives. This interface is used to communicate with a drive controller. SCSI drives use SCSI controllers, PATA drives use PATA controllers, and so on. When setting up a new server, you should give considerable thought to the drive configuration. Start by choosing drives or storage systems that provide the appropriate level of performance. There really is a substantial difference in speed and performance among various drive -specifications.
You should consider not only the capacity of the drive but also the following:
- Rotational speed A measurement of how fast the disk spins
- Average seek time A measurement of how long it takes to seek between disk tracks during sequential input/output (I/O) operations
Generally speaking, when comparing drives that conform to the same specification, such as Ultra320 SCSI or SATA II, the higher the rotational speed (measured in -thousands of rotations per minute) and the lower the average seek time (measured in milliseconds, or msecs), the better. As an example, a drive with a rotational speed of 15,000 RPM will give you 45 percent to 50 percent more I/O per second than the average 10,000 RPM drive, all other things being equal. A drive with a seek time of 3.5 msec will give you a 25 percent to 30 percent response time improvement over a drive with a seek time of 4.7 msec.
Other factors to consider include the following:
- Maximum sustained data transfer rate A measurement of how much data the drive can continuously transfer
- Mean time to failure (MTTF) A measurement of how many hours of operation you can expect to get from the drive before it fails
- Nonoperational temperatures Measurements of the temperatures at which the drive fails
Most drives of comparable quality will have similar transfer rates and MTTF. For example, if you compare Ultra320 SCSI drives with a 15,000 RPM rotational speed, you will probably find similar transfer rates and MTTF. For example, the Maxtor Atlas 15K II has a maximum sustained data transfer rate of up to 98 megabytes per second (MBps). The Seagate Cheetah 15K.4 has a maximum sustained data transfer rate of up to 96 MBps. Both have an MTTF of 1.4 million hours. Transfer rates can also be expressed in gigabits per second (Gbps). A rate of 1.5 Gbps is equivalent to a data rate of 188 MBps, and 3.0 Gbps is equivalent to 375 MBps. Sometimes you'll see a maximum external transfer rate (per the specification to which the drive complies) and an average sustained transfer rate. The average sustained transfer rate is the most important factor. The Seagate Barracuda 7200 SATA II drive has a rotational speed of 7,200 RPM and an average sustained transfer rate of 58 MBps. With an average seek time of 8.5 msec and an MTTF of 1 million hours, the drive performs comparably to other 7,200 RPM SATA II drives. However, most Ultra320 SCSI drives perform better and are better at multi-user read/write operations, too.
Temperature is another important factor to consider when you're selecting a drive—but it's a factor few administrators take into account. Typically, the faster a drive rotates, the hotter it will run. This is not always the case, but it is certainly something you should consider when making your choice. For example, 15K drives tend to run hot, and you must be sure to carefully regulate temperature. Both the Maxtor Atlas 15K II and the Seagate Cheetah 15K.4 can become nonoperational at temperatures of 70°C or higher (as would most other drives).
Preparing a Physical Drive for Use
After you install a drive, you'll need to configure it for use. You configure the drive by partitioning it and creating file systems in the partitions, as needed. A partition is a section of a physical drive that functions as if it were a separate unit. After you create a partition, you can create a file system in the partition.
Two partition styles are used for disks: Master Boot Record (MBR) and GUID Partition Table (GPT). Although both 32-bit and 64-bit editions of Windows Server 2008 support both MBR and GPT, the GPT partition style is not recognized by any earlier releases of Windows Server for x86 or x64 architectures.
The MBR contains a partition table that describes where the partitions are located on the disk. With this partition style, the first sector on a hard disk contains the Master Boot Record and a binary code file called the master boot code that's used to boot the system. This sector is unpartitioned and hidden from view to protect the system.
With the MBR partitioning style, disks support volumes of up to four terabytes (TB) and use one of two types of partitions—primary or extended. Each MBR drive can have up to four primary partitions or three primary partitions and one extended partition. Primary partitions are drive sections that you can access directly for file storage. You make a primary partition accessible to users by creating a file system on it. Unlike primary partitions, you can't access extended partitions directly. Instead, you can configure extended partitions with one or more logical drives that are used to store files. Being able to divide extended partitions into logical drives allows you to divide a physical drive into more than four sections.
GPT was originally developed for high-performance Itanium-based computers. GPT is recommended for disks larger than 2 TB on x86 and x64 systems, or any disks used on Itanium-based computers. The key difference between the GPT partition style and the MBR partition style has to do with how partition data is stored. With GPT, critical partition data is stored in the individual partitions and redundant primary and backup partition tables are used for improved structure integrity. Additionally, GPT disks support volumes of up to 18 exabytes and up to 128 partitions. Although underlying differences exist between the GPT and MBR partitioning styles, most disk-related tasks are performed in the same way.
Using Disk Management
You'll use the Disk Management snap-in for the Microsoft Management Console (MMC) to configure drives. Disk Management makes it easy to work with the internal and external drives on a local or remote system. Disk Management is included as part of the Computer Management console and the Server Manager console. You can also add it to custom MMCs. In Computer Management and in Server Manager, you can access Disk Management by expanding the Storage node and then selecting Disk Management.
Regardless of whether you are using Computer Management or Server Manager, Disk Management has three views: Disk List, Graphical View, and Volume List. With remote systems you're limited in the tasks you can perform with Disk Management. Remote management tasks you can perform include viewing drive details, changing drive letters and paths, and converting disk types. With removable media drives, you can also eject media remotely. To perform more advanced manipulation of remote drives, you can use the DISKPART command-line utility.
Note Before you work with Disk Management, you should know several things. If you create a partition but don't format it, the partition will be labeled as Free Space. If you haven't assigned a portion of the disk to a partition, this section of the disk is labeled Unallocated.
In Figure 12-1, the Volume List view is in the upper-right corner and the Graphical View is in the lower-right corner. This is the default configuration. You can change the view for the top or bottom pane as follows:
- To change the top view, select View, choose Top, and then select the view you want to use.
- To change the bottom view, select View, choose Bottom, and then select the view you want to use.
- To hide the bottom view, select View, choose Bottom, and then select Hidden.
Figure 12-1 In Disk Management the upper view provides a detailed summary of all the drives on the computer and the lower view provides an overview of the same drives by default.
Windows Server 2008 supports three types of disk configurations:
- Basic The standard fixed disk type used in previous versions of Windows. Basic disks are divided into partitions and can be used with previous versions of Windows.
- Dynamic An enhanced fixed disk type for Windows Server 2008 that you can update without having to restart the system (in most cases). Dynamic disks are divided into volumes and can be used only with Windows 2000 and later releases of Windows.
- Removable The standard disk type associated with removable storage devices. Removable storage devices can be formatted with exFAT, FAT16, FAT32, or NTFS.
Real World Both Windows Vista with SP1 or later and Windows Server 2008 support exFAT with removable storage devices. The exFAT file system is the next generation file system in the FAT (FAT12/16, FAT32) family. While retaining the ease-of-use advantages of FAT32, exFAT overcomes FAT32's 4-GB file size limit and FAT32's 32-GB partition size limit on Windows systems. exFAT also supports allocation unit sizes of up to 32,768 KB.
exFAT is designed so that it can be used with any compliant operating system or device. This means you could remove an exFAT storage device from a compliant camera and insert it into a compliant phone or vice versa without having to do any reformatting. It also means that you could remove an exFAT storage device from a computer running Mac OS or Linux and insert it into a computer running Windows.
From the Disk Management window, you can get more detailed information on a drive section by right-clicking it and then selecting Properties from the shortcut menu. When you do this, you see a dialog box. With fixed disks, the dialog box is much like the first one shown in Figure 12-2. With removable disks, the dialog box is much like the second one shown in Figure 12-2. This is the same dialog box that you can open from Windows Explorer (by selecting the top-level folder for the drive and then selecting Properties from the File menu).
Figure 12-2 The General tab of the Properties dialog box provides detailed information about a drive.
Removable Storage Devices
Removable storage devices can be formatted with NTFS, FAT, FAT32, and 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 universal serial bus (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, including USB 1.0, USB 1.1, USB 2.0, FireWire 400, and FireWire 800.
USB 2.0 is the industry standard and it supports data transfers at a maximum rate of 480 Mb per second, with sustained data transfer rates usually from 10 to 30 Mb 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 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 will be 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 2.0 device to a USB 1.0 port or vice versa, the device will operate at the significantly reduced USB 1.0 transfer speed.
USB 1.0, 1.1, and 2.0 ports all look alike. The best way to determine which type of USB ports a computer has is to refer to the documentation that came with a computer. Newer LCD monitors will 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 peer-to-peer architecture in which peripherals negotiate bus conflicts to determine which device can best control a data transfer. Like USB, several versions of FireWire currently are used, including FireWire 400 and FireWire 800. FireWire 400 (IEEE 1394a) has maximum sustained transfer rates of up to 400 Mb per second. FireWire 800 (IEEE 1394b) has maximum sustained transfer rates of up to 800 Mb per second. Similar to USB, if you connect a FireWire 800 device to a FireWire 400 port or vice versa, the device will operate at the significantly reduced FireWire 400 transfer speed.
FireWire 400 and FireWire 800 ports and cables have different shapes, making it easier to tell the difference between them—if you know what you're looking for. With that said, FireWire 400 ports and cables look exactly like early versions of FireWire that were implemented prior to the finalization of the IEEE 1394a and IEEE 1394b specifications. Early FireWire implementations 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 early FireWire and FireWire 400 apart by looking closely at the cables and ports. Early FireWire cables and ports have four pins and four connectors. FireWire 400 cables and ports have six pins and six connectors.
When you are purchasing an external device for a computer, you'll also want to consider what interfaces it supports. In some cases, you may be able to get a device with a dual interface that supports USB 2.0 and FireWire 400, or a triple interface that supports USB 2.0, FireWire 400, and FireWire 800. A device with dual or triple interfaces will give you more options.
Working with removable disks is similar to working with fixed disks. You can
- Right-click a removable disk and select Open or Explore to examine the disk's contents in Windows Explorer.
- Right-click a removable disk and select Format to format removable disks as discussed in "Formatting Partitions" on page 355. Removable disks generally are formatted with a single partition.
- Right-click a removable disk and 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" on page 358.
When you work with removable disks, you can customize disk and folder views. To do this, right-click the disk or folder and then 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 types 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 that 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 there isn't necessarily an underlying security architecture. With exFAT, FAT, or FAT32, folders and files stored do not have any security permissions or features other than the basic read-only or hidden attribute flags that you can set.
Installing and Checking for a New Drive
Hot swapping is a feature that allows you to remove devices without shutting off the computer. Typically, hot-swappable drives are installed and removed from the front of the computer. If your computer supports hot swapping of drives, you can install drives to the computer without having to shut down. After you do this, open Disk Management, and select Rescan Disks from the Action menu. New disks that are found are added with the appropriate disk type. If a disk that you've added isn't found, reboot.
If the computer doesn't support hot swapping of drives, you must turn the computer off and then install the new drives. Then you can scan for new disks as described previously. If you are working with new disks that have not been initialized—meaning they don't have disk signatures—Disk Management will start the Initialize And Convert Disk Wizard as soon it starts up and detects the new disks.
You can use the Initialize And Convert Disk Wizard to initialize the disks by following these steps:
- Click Next to exit the Welcome page. On the Select Disks To Initialize page, the disks you added are selected for initialization automatically, but if you don't want to initialize a particular disk, you can clear the related option.
- Click Next to display the Select Disks To Convert page. This page lists the new disks as well as any nonsystem or boot disks that can be converted to dynamic disks. The new disks aren't selected by default. If you want to convert the disks, select them and then click Next.
- The final page shows you the options you've selected and the actions that will be performed on each disk. If the options are correct, click Finish. The wizard then performs the designated actions. If you've elected to initialize a disk, the wizard writes a disk signature to the disk. If you've elected to convert a disk, the wizard converts the disk to a dynamic disk after writing the disk signature.
If you don't want to use the Initialize And Convert Disk Wizard, you can close it and use Disk Management instead to view and work with the disk. In the Disk List view, the disk will be marked with a red exclamation point icon, and the disk's status will be listed as Not Initialized. You can then right-click the disk's icon and select Initialize Disk. Confirm the selection (or add to the selection if more than one disk is available for initializing) and then click OK to start the initialization of the disk. Conversion to a dynamic disk would then proceed as discussed in "Converting a Basic Disk to a Dynamic Disk" on page 348.
Understanding Drive Status
Knowing the drive status is useful when you install new drives or troubleshoot drive problems. Disk Management shows the drive status in the Graphical View and Volume List view. Table 12-2 summarizes the most common status values.
Table 12-2 Common Drive Status Values
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