Windows Server 2003 : Preparing for a Disaster (part 1) - Creating Automated System Recovery Disks

As Ben Franklin was known to say, “Failure to prepare is preparing to fail.” This is truer than ever with modern operating systems, and although Windows Server 2003 includes a number of exceptionally useful recovery modes and tools, you still need to prepare for potential problems.

Setting Up a Fault-Tolerant System

A fault-tolerant system is one that is prepared to continue operating in the event of key component failures. This technique is very useful for servers running critical applications. Here are a few of the many ways to ensure fault tolerance in a system:

• Use one or more RAID arrays for system and data storage, protecting you from hard disk failure. If a hard disk in the array fails, only that disk needs to be replaced—and no data is lost. 

• Use multiple SCSI adapters to provide redundancy if a SCSI controller fails.

• Use an uninterruptible power supply (UPS) to allow the server to shut down gracefully in the event of a power failure.

• Use multiple network cards to provide redundancy in case a network card fails.

• Use multiples of everything that is likely to fail, including power supplies and so on.

• Use clusters to provide redundancy and failover in the event of a server failure.
  

Backing Up the System

Back up the system and system state regularly using a good Windows Server 2003 backup program. If a hard disk fails and must be replaced and you’re not using some sort of RAID array, the data and system can be restored from backup. (If you lose the system entirely, you’ll need to install Windows Server 2003 on it before restoring the original system.) 

Creating Automated System Recovery Disks

Whereas Microsoft Windows NT and Microsoft Windows 2000 created an emergency repair disk (ERD) to help rescue the system in the event of a disaster, the Windows Server 2003 family creates an Automated System Recovery (ASR) disk. The ASR disk contains important information that can be used to fix system files, the boot sector, and the startup environment. The ASR disk is easy to make, and it is very useful in the event of a disaster.

Note

In Windows Server 2003, you might have noticed that you didn’t get prompted to create an ERD during installation, as you do during Windows NT setup. In fact, the entire procedure has changed. Now, instead of an ERD, you run the Backup program in Windows Server 2003 to create an ASR disk and backup. To make a fresh ASR disk, you need a floppy disk that you don’t mind being formatted and a fresh tape for your tape drive (or fresh Zip disk, Jaz disk, hard drive, or other supported media, for your target backup device). Always use a freshly formatted floppy disk to create an ASR disk. It’s also a good idea to have a backup of your ASR disk, so always keep at least one generation back. We also like to keep an original ASR disk created immediately after the installation process as a kind of ultimate fallback position.

To make an ASR disk, follow these steps:

1.	Open the Windows Server 2003 Backup program from the Start menu by pointing to Programs, Accessories, and System Tools and then choosing Backup.
2.	Switch to the Advanced Mode if you get a wizard prompt.
3.	Click Automated System Recovery Wizard, as shown in Figure 1 to open the Automated System Recovery Preparation Wizard, shown in Figure 2. Click Next. Figure 1. The Windows Server 2003 Backup Utility window Figure 2. The Automated System Recovery Preparation Wizard
4.	In the Backup Destination page shown in Figure 3, select the backup type and destination you’ll be using. Windows Server 2003 doesn’t support directly writing to CD or DVD, but you can write to any device that is supported by the Windows Backup program. Click Next. Figure 3. The Backup Destination page
5.	Click Finish to complete the wizard. The backup starts automatically when you exit the wizard, as shown in Figure 4. Figure 4. The Backup Progress dialog box
6.	Once the backup has completed, you’ll be prompted to insert a blank floppy disk to create the ASR disk, as shown in Figure 5. Figure 5. Insert a formatted, blank floppy disk for ASR to use
7.	Insert a blank floppy disk in drive A, and click OK.
8.	Backup writes the necessary files to the floppy disk and confirms that the process has been successful, as shown in Figure 6. Label the disk and the backup media used as requested, and store them in a safe place. Figure 6. The Windows Backup Utility confirms the successful creation of the ASR disk

Note

The ASR disk is not bootable; it must be used in conjunction with the Windows Server 2003 installation media.

Under the Hood: Using the ASR Set Effectively

What, exactly, is on the ASR disk? Well, certainly not all the stuff that used to be there in Windows NT. Instead of trying to fit all the files necessary to recover your system onto a single floppy disk, a task that had become more than a little problematic, Windows Server 2003 now copies only the following three files to the floppy:

• Setup.log Points to the location of system files on your server

• Asr.sif Contains information on disk, partitions and volumes on the system, and the location of the backup media used

• Asrpnp.sif Contains information on the various plug and play devices on the system

With this change, it’s easy to maintain multiple generations of repair information because each ASR disk points to a specific system backup. You should always keep the ASR disk with the specific backup that it was made with.

Whenever you make a major change to your system, it’s a good idea to make a fresh ASR set before you make the change. This gives you a fallback position if something goes wrong. If something doesn’t work right, you can quickly restore the previous configuration. Once you’ve confirmed that the new configuration is stable and working, then and only then should you update your ASR set for that server.

What constitutes a major change? Adding, removing, or otherwise modifying the hard disks or their partitions, formats, configurations, and so on is one category of major changes. Any time you make a change to the hard disk configuration, you’ll definitely want to make a fresh ASR set just before you make the change. Another major change would be the addition of a new component to the server, such as adding Microsoft Exchange Server or Microsoft SQL Server. Any changes made from Control Panel are candidates for redoing the ASR set as well.