CompTIA Security_ Deluxe Study Guide_ SY0-201 - Emmett Dulaney [213]
Backup Server method The costs of disk storage and servers have fallen tremendously over the past few years. Lower prices have made it easier for organizations to use dedicated servers for backup. The Backup Server method establishes a server with large amounts of disk space whose sole purpose is to back up data. With the right software, a dedicated server can examine and copy all the files that have been altered every day.
Figure 8.6 illustrates the use of backup servers. In this instance, the files on the backup server contain copies of all the information and data on the APPS, ACCTG, and DB servers. The files on the three servers are copied to the backup server on a regular basis; over time, this server’s storage requirements can become enormous. The advantage of this method is that all backed-up data is available online for immediate access.
This server can be backed up on a regular basis, and the backups can be kept for a specified period. If a system or server malfunctions, the backup server can be accessed to restore information from the last backups performed on that system.
Backup servers don’t need overly large processors; however, they must have large disk and other long-term storage media capabilities. Several software manufacturers take backup servers one additional step and create hierarchies of files: Over time, if a file isn’t accessed, it’s moved to slower media and may eventually be stored offline. This helps reduce the disk storage requirements, yet it still keeps the files that are most likely to be needed for recovery readily available
FIGURE 8.6 A backup server archiving server files
Many organizations utilize two or more of these methods to back up systems. The issue becomes one of storage requirements and retention requirements. In establishing a backup plan, you must ask users and managers how much backup (in terms of frequency, size of files, and so forth) is really needed and how long it will be needed.
Make sure you obtain input from all who are dealing with governmental or regulatory agencies. Each agency may have different archival requirements, and compliance violations can be expensive. Both HIPAA and Sarbanes-Oxley are affecting—and driving—archival and disposal policies around the nation.
Recovering a System
When a system fails, you’ll be unable to reestablish operation without regenerating all of the system’s components. This process includes making sure hardware is functioning, restoring or installing the operating systems, restoring or installing applications, and restoring data files. It can take several days on a large system. With a little forethought, you may be able to simplify the process and make it easily manageable.
When you install a new system, make a full backup of it before any data files are created. If stored onsite, this backup will be readily available for use. If you’ve standardized your systems, you may need just one copy of a base system that contains all the common applications you use. The base system can usually be quickly restored, which allows for reconnection to the network for restoration of other software. Many newer operating systems now provide this capability, and system restores are very fast.
Figure 8.7 demonstrates this process further. Notice that the installation CDs are being used for the base OS and applications.
FIGURE 8.7 System regeneration process for a workstation or server
When the base system has been restored, data files and any other needed files can be restored from the last full backup and any incremental or differential backups that have been performed. The last full backup should contain most of the data on the system; the incremental backup or differential backups contain the data that has changed since the full backup.
Many newer operating systems, such as Windows Server 2008, allow you to create a model user system as a disk image on a server;