Microsoft Windows XP Professional Resource Kit 2003
ISBN: N/A
EAN: N/A
EAN: N/A
Year: 2005
Pages: 338
Pages: 338
When you develop your backup plan:
Keep spare hardware and media on hand in case of a failure. To avoid a problem, compare the spare hardware with the original hardware in advance to make sure that the firmware revision is the same as the original equipment. For more information about firmware revisions, check the documentation provided by the manufacturer.
Test backed-up data regularly to verify the reliability of your backup procedures and equipment.
Include stress testing of backup hardware (storage drives, optical drives, and controllers) and software (backup program and device drivers).
Several different system configurations can affect your backup strategies. At one end of the range is a simple, stand-alone computer with one user. At the other is a workgroup network with a computer that is hosting a network public file share.
| Caution | Backup does not back up files on computers running Microsoft MS DOS , unless you create a share that Backup can access over the network. Consider reserving space on a network share so that users of MS DOS and Microsoft Windows version 3.1 can copy important files. Files on the network share can be backed up during regular file server backups. |
You can work out a backup solution by doing these four tasks:
Research and select a storage device. When considering new backup hardware, be sure to consider its reliability, speed, capacity, cost, and compatibility with Windows XP Professional. The media must provide more than enough space to back up all of your data.
If necessary, install a controller card in the computer. If you choose to use a SCSI-based tape drive, put the tape drive on its own controller.
Connect your new storage device to the computer so that you can back up the System State data. If you are using an external SCSI drive, start the drive before you start the computer so that the driver can be loaded properly.
Establish a backup media rotation schedule. You need to continue making backups as long as data is created or changed.
Over a period of time, you need to use several separate discs or tapes when you run your backup regimen. By using multiple discs or tapes instead of repeatedly using the same disc or tape, you gain additional benefits with your backup program:
It preserves access to multiple versions of data files in case a user needs to restore an older copy of a data file.
If the last backup is unsuccessful as a result of a bad cartridge, you have a backup from the previous process.
You extend the useful life span of each cartridge.
| Tip | Have several extra, new, blank, formatted media available in case of media failure. Regularly scan the Backup log for errors that might indicate that a backup cartridge is beginning to fail. Make sure to clean a tape drive s recording heads regularly. Failure to do so can lead to unusable backups and the premature failure of the tape drive. See the tape drive manufacturer s recommendations for the proper method and frequency of cleaning. |
You need to choose a backup medium to use. If the quantity of data that you need to back up is small, a removable hard disk or rewritable DVD disc (DVD RAM) might be all that you need. However, for more flexibility and capacity for growth, a tape cartridge is still the backup medium of choice.
To back up to a CD R or CD RW, you must back up to a file first, and then copy that file to the CD R or CD RW. You can then restore the file directly from the CD R or CD RW. Because space on CD R or CD RW is limited from 650 to 700 MBs, you might have to divide your backups into smaller jobs.
After your storage device is installed, decide on a backup schedule and the type of backup. If the data that is created on a daily basis is irreplaceable, daily backups are recommended. If the data is less valuable, the frequency of backups can be less often. Recognize, however, that the longer the period between backups, the greater the potential for loss. Just as it is unwise to work on a document all day without saving the file, it is unwise to work on a document all week without backing it up. The value of the data helps you determine the appropriate frequency of backups.
The type of backup you make determines how easy or difficult it is to restore the data in an emergency. The compromise is between security and convenience. If you choose to run full, normal backups every day, you can restore lost data easily, but the backups can take a substantial amount of time (depending upon the quantity of data to be backed up and the data transfer speed of the storage device). If you choose to make incremental backups for a month after making a full backup, you save substantial time in the backup process. However, fully restoring a corrupted hard disk might require you to restore the normal backup, and then each incremental backup in succession. Substituting a differential backup for the incremental backup shortens the restore process, but as the backup process takes more time each day, the total accumulation of changed files continues to grow, so the time you gain by using a differential backup might be minimal. You must also use a separate cartridge for each differential backup to prevent losing the ability to retrieve earlier versions of files.
Computers that contain frequently changing data that is hard to replace or reproduce, or computers that provide a public network share need to be backed up daily. Run a full, normal backup every Friday. Every Monday through Thursday run a differential backup to a different tape or disc. After the second Friday, when a second full backup has been successfully made, store the first full backup as a temporary archive. Then after every following Friday s full backup, alternate the full backups as temporary archives. On every eighth Friday, save the full backup as a permanent archive, which needs to be stored in a secure, off-site location. Over the course of a year, this method uses at least 14 tapes or discs.
| Note | If a computer is used seven days a week, add a Saturday and Sunday differential backup to the schedule. Use new tapes if you choose to make permanent archives on tape. |
If the computer is used less often or if the data is not as valuable, consider making one incremental backup each week for three weeks and one full, normal backup every fourth week. Alternating the full backups between two cartridges ensures that at least one always exists. This reduces the amount of time spent creating backups, but it also reduces protection against data corruption or erasure. Over the course of a year this method uses at least fives tapes or discs.
The following scenario illustrates a possible approach for backing up a small network that consists of a computer that is running Windows XP Professional and that is hosting a public file share for 20 other client computers.
Connect a storage device to the share host computer. From the share host computer, you can back up user files on remote computers that are running the following operating systems: Microsoft Windows for Workgroups, Microsoft Windows 95, Microsoft Windows 98, Microsoft Windows NT 4.0 , Microsoft Windows 2000, and Windows XP Professional. (See the two suggested methods for doing this that follow.) Establish a media rotation schedule. If conserving media is a requirement, back up clients less frequently than you back up the share host and encourage users to copy critical files to the network share at the end of the day.
Volume shadow copies cannot be used on remote shares. The success of your backup is more reliable if it is run on an individual Windows XP Professional based computer and saved to the server that you are backing up. Using this method provides a shadow copy of the data volumes, and you can then schedule periodic system state backups. However, this backup method must be managed and scheduled for each computer individually, which is not practical if you manage many computers.
In the descriptions of the following methods for backing up remote computers, the computer that contains the data to be backed up is called Data. The computer that runs the backup process is called Target.
Back up Data locally to disk. Use Backup over the network or the xcopy command to move the resulting backup file to Target. Make sure you run a backup verification pass that compares the data on Data and the data on Target on a regular basis. Typical transfer speeds for Ethernet or Token Ring are approximately 1 megabyte (MB) per second if the network is not busy. You can use this transfer rate and the total amount of data being transferred to estimate the transfer time. If the transfer time is too long, you might need to use a faster network connection or a different backup method.
For more information about using the xcopy command, type the following at the command prompt:
xcopy /?
Copy the data that you want to back up to another disk or disks on Data. Bring Data online, and copy the data by using the data storage device that is connected to Data. You can also back up Data over the network to Target. Whether to perform the backup from Data or from Target depends on the following factors:
Availability of a target computer
Policies requiring backups on designated computers
Time and cost of performing backup from Data
Time and cost of transferring files to Target
After you have determined the best method for giving Target access to the data it needs to back up, you can begin your backup schedule plan. On Target, run a full, normal backup every Friday. Every Monday through Thursday, run a differential backup to a different tape. Run this program for four weeks before you reuse tapes in the backup program. On every fourth Friday, save the full backup as a permanent archive stored in a secure, off-site location. Over the course of a year, this method uses at least 31 tapes.
| Note | To allow users access to even more old versions of document files, you can lengthen the backup schedule to six weeks before tapes are reused. This increases the number of tapes used in a year to at least 41. If a computer is used seven days a week, add a Saturday and Sunday differential backup to the schedule. |
Keeping accurate backup records is essential for locating backed up data quickly, particularly if you have accumulated a large number of backup cartridges. Thorough records include cartridges labels, catalogs, and online log files and log books.
Labels for write-once cartridges need to contain the backup date, the type of backup (normal, incremental, or differential), and a list of contents. If you are restoring from differential or incremental backups, you need to be able to locate the last normal backup and either the last differential backup or all incremental backups that have been created since the last normal backup. Label reusable media, such as tapes or removable discs, sequentially and keep a log book in which you note the content of cartridges, the backup date, the type of backup, and the date the medium was placed in service. If you have to replace a defective cartridge, label the new cartridge with the next unused sequential ID, and record it in the log book.
Most backup software includes a mechanism for cataloging backup files. Backup stores catalogs on a backup cartridge and temporarily loads them into memory. Catalogs are created for each backup set or for each collection of backed up files from one drive.
Log files include the names of all backed up and restored files and folders. A log file is useful when you are restoring data because you can print or read this file from any text editor. Keeping printed logs in a notebook makes it easier to locate specific files. For example, if the tape that contains the catalog of the backup set is corrupted, you can use the printed logs to locate a file. It is recommended that you carefully review log files following each backup session to ensure that the session completes successfully.
A verify operation compares the files on disk to the files on the backup media. It occurs after all files are backed up or restored, and it takes about as long as the backup procedure. Recommended times for performing verify operations follow:
After every backup, especially if you back up to a set of cartridges for long-term storage.
After a file restore operation.
Choosing a verify operation while backing up system files might cause the verify operation to falsely report files that are in use by the operating system and continuously changing.
If a verify operation is unsuccessful for a particular file, check the date that the file was last modified. If the file changes between a backup operation and a verify operation, the verify operation is unsuccessful. A change in the size of a file, or corruption of data on the backup disc or cartridge also might make a verify operation unsuccessful.