Managing File Systems and Drives in Windows Server 2008

  • 12/28/2009

Adding Hard Disk Drives

Before you make a hard disk drive available to users, you need to configure it and consider how it will be used. With Windows Server 2008 R2, 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 R2 supports drive sets and arrays using redundant array of independent disks (RAID) technology, which is built into the operating system.

Physical Drives

Whether you use individual drives or drive sets, you 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 500 gigabytes (GB) to 2 terabytes (TB). Many drive types are available for use with Windows Server 2008 R2, 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 gives you 45–50 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 gives you a 25–30 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 have similar transfer rates and MTTF. For example, if you compare Ultra320 SCSI drives with 15,000 RPM rotational speed from different vendors, 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 187.5 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 multiuser 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 runs. 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 degrees Centigrade or higher (as would most other drives).

Preparing a Physical Drive for Use

After you install a drive, you 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). 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 4 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. Although you can access primary partitions directly, 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 structural integrity. Additionally, GPT disks support volumes of up to 18 exabytes and as many as 128 partitions. Although the GPT and MBR partitioning styles have underlying differences, most disk-related tasks are performed in the same way.

Using Disk Management

You 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.

In Figure 12-1, the Volume List view is in the upper-right corner and Graphical View is used 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

    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 R2 supports four 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 R2 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, FAT, FAT32, or NTFS.

  • Virtual The virtual hard disk (VHD) disk type associated with virtualization can be used when a computer is running Windows 7, Windows Server 2008 R2, or later releases. Computers can use VHDs just like they use regular fixed disks and can even be configured to boot from a VHD.

From the Disk Management window, you can get more detailed information on a drive section by right-clicking it and then selecting Properties. When you do this, you see a dialog box. With fixed disks, the dialog box is much like the one shown on the left in Figure 12-2. With removable disks, the dialog box is much like the one shown on the right 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 choosing Properties from the File menu).

Figure 12-2

Figure 12-2. The General tab of the Properties dialog box provides detailed information about a drive.

If you’ve configured remote management through Server Manager and MMCs, as discussed in Chapter 3, "Managing Servers Running Windows Server 2008 R2" you can use Disk Management to configure and work with disks on remote computers. Keep in mind, however, that your options are slightly different from when you are working with the disks on a local computer. Tasks you can perform include:

  • Viewing limited disk properties but not volume properties. When you are viewing disk properties, you’ll see only the General and Volumes tabs. You won’t be able to see volume properties.

  • Changing drive letters and mount paths.

  • Formatting, shrinking, and extending volumes. With mirrored, spanned, and striped volumes, you are able to add and configure related options.

  • Deleting volumes (except for system and boot volumes)

  • Creating, attaching, and detaching VHDs. When you create and attach VHDs, you need to enter the full file path and won’t be able to browse for the .vhd file.

Some tasks you perform with disks and volumes depend on the Plug and Play and Remote Registry services.

Removable Storage Devices

Removable storage devices can be formatted with 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 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 Mbps, with sustained data transfer rates usually from 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 2.0 device to a USB 1.0 port or vice versa, the device operates 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 comes with the computer. Newer LCD 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 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 Mbps. FireWire 800 (IEEE 1394b) has maximum sustained transfer rates of up to 800 Mbps. As with USB, if you connect a FireWire 800 device to a FireWire 400 port or vice versa, the device operates 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. 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 cables always have bus power and have nine pins and nine connectors.

Another option is External Serial ATA (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 3 Gbps. 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 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 gives you more options. There also are devices with quadruple interfaces.

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

  • 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 a removable disk as discussed in "Formatting Partitions" later in this chapter. 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" later in this chapter.

When you work with removable disks, you can customize disk and folder views. To do this, right-click the disk or folder, select Properties, 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 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 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 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.

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 without having to shut down. After you do this, open Disk Management, and then choose 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 Disk dialog box as soon it starts up and detects the new disks.

You can initialize the disks by following these steps:

  1. Each disk you install needs to be initialized. Select the disk or disks that you installed.

  2. Disks can use either the MBR or GPT partition style. Select the partition style you want to use for the disk or disks you are initializing.

  3. Click OK. If you elected to initialize disks, Windows writes a disk signature to the disks and initializes the disks with the basic disk type.

If you don’t want to use the Initialize Disk dialog box, you can close it and use Disk Management instead to view and work with the disk. In the Disk List view, the disk is marked with a red downward pointing arrow icon, the disk’s type is listed as Unknown, and the disk’s status is listed as Not Initialized. You can then right-click the disk’s icon and select Online. Right-click the disk’s icon again, and select Initialize Disk. You can then initialize the disk as discussed previously.

Understanding Drive Status

Knowing the status of a drive is useful when you install new drives or troubleshoot drive problems. Disk Management shows the drive status in Graphical View and Volume List view. Table 12-2 summarizes the most common status values.

Table 12-2. Common Drive Status Values

STATUS

DESCRIPTION

RESOLUTION

Online

The normal disk status. It means the disk is accessible and doesn’t have problems. Both dynamic disks and basic disks display this status.

The drive doesn’t have any known problems. You don’t need to take any corrective action.

Online (Errors)

I/O errors have been detected on a dynamic disk.

You can try to correct temporary errors by right-clicking the disk and selecting Reactivate Disk. If this doesn’t work, the disk might have physical damage or you might need to run a thorough check of the disk.

Offline

The disk isn’t accessible and might be corrupted or temporarily unavailable. If the disk name changes to Missing, the disk can no longer be located or identified on the system.

Check for problems with the drive, its controller, and cables. Make sure that the drive has power and is connected properly. Use the Reactivate Disk command to bring the disk back online (if possible).

Foreign

The disk has been moved to your computer but hasn’t been imported for use. A failed drive brought back online might sometimes be listed as Foreign.

Right-click the disk, and then click Import Foreign Disks to add the disk to the system.

Unreadable

The disk isn’t accessible currently, which can occur when disks are being rescanned. Both dynamic and basic disks display this status.

With FireWire and USB card readers, you might see this status if the card is unformatted or improperly formatted. You might also see this status after the card is removed from the reader. Otherwise, if the drives aren’t being scanned, the drive might be corrupted or have I/O errors. Right-click the disk, and then click Rescan Disk (on the Action menu) to try to correct the problem. You might also want to reboot the system.

Unrecognized

The disk is of an unknown type and can’t be used on the system. A drive from a non-Windows system might display this status.

If the disk is from another operating system, don’t do anything. You can’t use the drive on the computer, so try a different drive.

Not Initialized

The disk doesn’t have a valid signature. A drive from a non-Windows system might display this status.

If the disk is from another operating system, don’t do anything. You can’t use the drive on the computer, so try a different drive. To prepare the disk for use on Windows Server 2008 R2, right-click the disk, and then click Initialize Disk.

No Media

No media has been inserted into the CD-ROM or removable drive, or the media has been removed. Only CD-ROM and removable disk types display this status.

Insert a CD-ROM, a floppy disk, or a removable disk to bring the disk online. With FireWire and USB card readers, this status is usually (but not always) displayed when the card is removed.