Different Types of Disasters

Typically, the four types of disasters you might experience are as follows:

• Critical data other than the operating system (OS) or the Backup software is damaged or destroyed. This disaster applies to both Backup clients and servers.

  In the example shown in Figure 1-1, a Backup client has two disks. The disk containing the operating system and Backup software is still operational, but the second disk, containing critical client data, was destroyed by a disk crash. To recover from this disaster, use the Backup recover program to recover the lost applications and data.

  Figure 1-1 Critical Data is Lost on a Secondary Disk

  
  

• In Figure 1-2, the operating system has been damaged or destroyed. This situation can occur on Backup clients and servers.

  In the example, a Backup server has several physical disks. A power outage corrupted the filesystem on Disk 0, which destroyed the operating system. To recover from the disaster, you need to replace the disk, reinstall the operating system, and if necessary, the Backup software. Then use Backup to recover the lost server configuration and any data that was lost when the operating system was destroyed.

  Figure 1-2 Disk Containing Operating Software is Damaged

  
  

  ---

  Caution -

  In a situation where the operating system was destroyed, you must always reinstall the operating system, reinstall Backup, and then use Backup to recover the remainder of your data. You cannot recover data backed up by Backup without reinstalling the operating system and Backup software first.

  ---

• In Figure 1-3, the directory on the server that contains the Backup software and the online indexes and configuration files has been damaged or destroyed. The operating system is assumed to be running on a different disk than the Backup software. This situation only applies to Backup servers.

  In the example, a single disk on a Backup server contains the Backup software and the index and configuration files. To recover from a disaster of this type, recover the contents of the bootstrap save set.

  Figure 1-3 Disk Containing Backup Indexes is Damaged

  
  

• In the example in Figure 1-4, the Backup server has been destroyed. To recover from this disaster, you need to recover all the data to a new system by the same name. This applies only to Backup servers.

  Figure 1-4 Backup Server is Destroyed