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Lesson 11

Linux Tools Designed To Help Protect Aginst Data Loss Conclusion

This module introduced you to Linux tools designed to help you protect against loss of data. You learned that Red Hat Linux supports tape drives for use as backup devices. The common types of tape drive hardware are:
  1. SCSI (usually DAT and DDS)
  3. "Floppy"

mt tape operations including rewind, offline, and erase are used to manipulate these drives.
Next, you learned about the tar, dump, and restore commands. The tar command creates archives and extracts files and directories from tar archives. The dump command offers a more extensive set of backup options by allowing incremental as well as full dumps to be performed. The restore command is a companion to dump and is used to recover file systems that have been backed up using the dump command.
Finally, you learned about RAID. RAID is a powerful tool to protect data from loss and inaccessibility. Various levels of RAID are available for use. The need for data redundancy, availability, and the amount of disk space and spare disks determine what level of RAID is appropriate. RAID 1 (mirroring) and RAID 5 (striping and parity) are the levels most commonly used. Cost and performance issues affect the selection of hardware or software RAID. Hardware RAID improves processing performance by carrying out some of the calculations needed for its operation; however, it is more expensive.

Learning objectives

Having completed this module, you should be able to:
  1. List the kinds of tape-drive hardware supported by Linux
  2. Recognize tape control commands
  3. Use the tar command to back up and restore files and directories
  4. Use the dump command to back up file systems
  5. Use the restore command to recover file systems
  6. List tape backup applications available from Red Hat
  7. Explain basic concepts related to RAID
  8. Describe RAID levels
  9. Compare and contrast hardware and software RAID

Glossary terms

This module introduced you to the following terms:
  1. ATAPI/IDE: ATAPI (AT Attachment Packet Interface) is a standard for connecting CD-ROM and tape backup drives to your computer via a standard hardware interface, and is part of the Enhanced IDE. Generally, IDE (Integrated Drive Electronics) is used as an interface to address hard disk drives.
  2. Mirroring: Mirroring uses n partitions that all store the same data for data redundancy and decreased read time.
  3. Parity: Parity is the calculation of an additional stripe from the normal data stripes, to be used to recover lost data in the event of a drive failure.
  4. QIC-80: QIC 80 is a tape standard that can be used to determine which tapes or devices will work with a particular operating system or backup utility.
  5. SCSI: Small Computer Systems Interface is a standard for connecting peripherals to your computer via a standard hardware interface.
  6. Striping: Striping is the arrangement of contiguous disk blocks across multiple drives instead of within the same drive. Striping is intended to increase the efficiency of disk access by allowing concurrent seeks on multiple devices.

The next module discusses how to administer local file systems.

Protecting Against DataLoss - Quiz

Before moving on to the next module, click the Quiz link below to test your understand of how to protect against loss of data.
Protecting Against DataLoss - Quiz