- Optimizing Disk Management for Fault Tolerance
- Maximizing Redundancy and Flexibility with Distributed File System
- Simplifying Fault Tolerance with Volume Shadow Copy
- Optimizing Disk Utilization with Remote Storage
- Optimizing Clusters to Simplify Administrative Overhead
- Leveraging Network Load Balancing for Improved Availability
- Realizing Rapid Recovery Using Automated System Recovery (ASR)
Optimizing Disk Utilization with Remote Storage
Another fault tolerance technique devised in Windows Server 2003 to protect the file system is Remote Storage. When it is installed and configured, Remote Storage has the ability to migrate eligible files from an NTFS volume to a library of magnetic or optical tapes, thus freeing up space on the production server's managed volume. The eligibility is determined in the configuration of Remote Storage based on certain criteria: the percentage of free space on the volume, the size of the files, and a time period over which the files have not been accessed.
When Remote Storage migrates a file or folder, it is replaced on the volume with a file link called a junction point. Junction points take up very little room, which reduces the amount of used disk space but leaves a way for this data to be accessed later in the original location. When a junction point is accessed, it spawns the Remote Storage service to retrieve the file that was migrated to tape.
Not Available on Windows XP or the Standard and Web Editions of Windows Server 2003
Remote Storage functionality is only available in Windows Server 2003 Enterprise and Datacenter editions. It is not available on Windows XP or the standard and Web editions of Windows Server 2003.
The next section explains how Remote Storage is configured and provides best practices for its use.
Configuring Remote Storage
Remote Storage is not installed by default in Windows Server 2003, but is easily added from the install media through the familiar Add/Remove Windows Components section of the Add or Remove Programs applet. Once installed, the administrator must configure the backup device that will be used, allocate backup media, and then configure the settings Remote Storage will use to determine whether files should be migrated to the media.
Remote Storage Supports All SCSI Class 4mm, 8mm, DLT, and Magneto-Optical Devices
Remote Storage supports all SCSI class 4mm, 8mm, DLT, and magneto-optical devices that are supported by Removable Storage. Using Remote Storage with Exabyte 8200 tape libraries is not recommended. Remote Storage does not support QIC tape libraries or rewritable compact disc and DVD formats.
Configuring the Backup Device
Ideally the backup device to be used in conjunction will be a tape library, so that file retrieval from junction points can occur automatically.
To enable a device, follow these steps:
Install the backup device or library on the Windows Server 2003 system. Use the backup device manufacturer's documentation to accomplish this process.
After the backup device is connected, boot up the server and log on using an account with Local Administrator access.
Click Start, All Programs, Administrative Tools, Computer Management.
In the left pane, if it is not already expanded, double-click Computer Management (local).
Click the plus sign next to Storage.
Click the plus sign next to Removable Storage.
Click the plus sign next to Libraries.
Right-click the library (backup device) and select Properties.
On the General tab of the Device Properties page, check the Enable Drive box, and click OK.
Allocating Media for Remote Storage
After the backup device is configured, tape media needs to be allocated for Remote Storage usage. New, unused media inserted into the device is placed in the free media pool. Previously used media will be placed in the import, unrecognized, or backup media pools. Remote Storage uses the Remote Storage media pool, but will look in the free media pool if it does not find available media in Remote Storage.
Specify the Type
Remote Storage can support only a single tape or disk type for use as Remote Storage. Specify the type during the Remote Storage Setup Wizard process.
To inventory a backup device and allocate media for Remote Storage, follow these steps:
Locate the desired device, as outlined in the preceding section. Then right-click the device and choose Inventory.
After the device completes the inventory process, select the backup device in the left pane. The media will then be listed in the right pane.
Right-click the media listed in the right pane and select Properties.
On the Media tab of the Media Properties page, note the media pool membership in the Location section. Figure 22.6 shows media that are part of the Import\DLT media pool.
Click Cancel to close the Media Properties page.
Figure 22.6 Removable media in the Import\DLT media pool.
Configuring Remote Storage Settings
After the backup device and media are properly configured and allocated, a volume can be managed by configuring Remote Storage settings. To configure a managed volume, follow these steps:
Click Start, All Programs, Administrative Tools, Remote Storage.
If this is the first time the Remote Storage console has been opened or no volumes on the server have been configured for Remote Storage management, the Remote Storage Wizard will begin. Click Next on the Welcome screen to continue.
On the Volume Management page, choose whether to manage all volumes or manage only selected volumes by selecting the appropriate radio button. In this example, select Manage Selected Volumes, and click Next.
Select the volume to manage and click Next.
On the Volume Settings page, enter the amount of free space for the managed volume.
On the same page, configure the minimum file size before it will be migrated by Remote Storage; then configure the number of days a file must remain unaccessed before Remote Storage will make it a possible candidate for migration, and then click Next.
Figure 22.7 shows a volume setting that will migrate data to Remote Storage when a volume has 10% free space remaining, and the file that will be migrated must be larger than 12KB and must remain unaccessed for 120 days.
On the Media Type page, choose the media type associated with the backup device enabled for Remote Storage to use. Choose a media type from the Media Types pull-down menu.
On the next page, you can configure a schedule to perform the file copy. The default is to run at 2 a.m. seven days a week. Click the Change Schedule button to configure a custom schedule or click Next to accept the default schedule.
Click Finish on the Completing the Remote Storage Wizard page to complete the process.
Figure 22.7 Setting typical Remote Storage volume settings.
Using Remote Storage
Remote Storage is a powerful new feature of Windows Server 2003, but if used improperly it can make an administrator's job more difficult. When setting up a Remote Storage to provide volume-level fault tolerance, keep the following best practices in mind:
Continue to perform backups. Remote Storage is not a replacement for running normal scheduled backups. It is also important to provide fault tolerance to Remote Storage itself by backing up the Remote Storage database. It is also a good practice to schedule Remote Storage migration activity to occur at a different time than normal scheduled backups, especially if both rely on the same backup tape library.
Set antivirus software to scan files only on access. If antivirus programs are scanning volumes managed by Remote Storage on a regular schedule, any data previously migrated by Remote Storage might be requested and be migrated back to disk.
Do not enable Remote Storage on DFS targets configured for replication. If a new target is added to a replicating DFS link, the entire contents of that DFS target folder will be read by the File Replication Service (FRS). This read operation is necessary to generate the staging files in preparation for synchronizing the target data, which again would cause migrated files to be restored back to the volume.
Validate Remote Storage functionality. It is important to schedule validation of managed volumes on a regular basis. Validation ensures that all files on managed volumes point to the correct data in Remote Storage.