Before you start
Objectives: learn where to find and how to use Backup tool to back up and restore files in XP.
Prerequisites: no prerequisites.
Key terms: file, restore, incremental, differential, archive, system, bit, mode, reset
Backup Overview
System State
The system state data includes the operating system configuration information for the system. It includes the Registry, COM+ Class Registration database, system files, boot files, files under Windows File Protection, and the Certificate Services database. System state should be backed up in regular intervals and also anytime we make a configuration change. During a system data backup, all system data is backed up (system data cannot be backed up selectively in portions). System state data can only be restored locally. It cannot be restored to a remote system.
Archive Bit
All files on our system have an attribute called the Archive attribute that plays the key role when doing backup. Archive attribute or bit is set every time a file gets changed or modified. That means that the system automatically flags the file as needing to be archived. When the file is backed up, the backup method may reset (clear) the archive bit to indicate it has been backed up.
Full Backup
When we do a normal or full backup, we actually back up every file regardless of the archive bit. In full backup archive bit is reset so the next time the file is changed, it will be marked as needing to be backed up. To restore, we only restore the last backup.
Incremental Backup
When doing incremental backup we only backup files that have the archive bit set. When those files are backed up, the archive bit is reset.
Differential Backup
When doing differential backup we backup files which have the archive bit set, but after the backup the archive bit is not reset.
Copy Backup
When doing ‘copy’ backup, we backup all file regardless of the archive bit, but the archive bit is not reset after the backup is finished.
Choose the Right Backup Strategy
Knowing when the archive bit gets set and when it gets reset is important if we are planing some kind of backup strategy. For example, doing incremental backup takes less time because every time the archive bit gets reset so we know that the files have been backed up. But doing a restore from an incremental back up takes more time, because we have to restore every single instance of incremental backup that occurred after the full backup.
For example, let’s imagine that we take the full backup on Sunday, then incremental backup on Monday (files that have been modified since the last full backup), incremental backup on Tuesday (files that have been modified since the last incremental backup), incremental backup on Wednesday (files that have been modified since the last incremental backup), incremental backup on Thursday (files that have been modified since the last incremental backup), incremental backup on Friday (files that have been modified since the last incremental backup) and incremental backup on Saturday (files that have been modified since the last incremental backup). Remember, when doing incremental backup we only backup files that have been modified. Because of that, backup is fast. Let’s say that we want to restore lost data from this kind of backup. First we have to restore the full backup, then the one made on Monday, then on Tuesday, then on Wednesday, then Thursday and so on. As we see, doing restore from incremental backup is slow and complex.
Remember, when doing differential backup we only backup files that have the archive bit set (files that have been modified). In contrast to incremental backup, differential backup does not reset the archive bit. Let’s say that we take a full backup on Sunday, then differential backup on Monday (files that have been modified since the last full backup), differential backup on Tuesday (all files that have been modified since the last full backup), differential backup on Wednesday (all files that have been modified since the last full backup), differential backup on Thursday (all files that have been modified since the last full backup), differential backup on Friday (all files that have been modified since the last full backup) and differential backup on Saturday (all files that have been modified since the last full backup). Remember, differential backup does not reset the archive bit. That means that all differential backups will contain all data that was modified since the last full backup. For example, differential backup done on Wednesday will also contain files modified on Monday and Tuesday. Differential backup done on Saturday will also contain files modified on Monday, Tuesday, Wednesday, Thursday and Friday. Because of that doing a differential backup takes more time and space as wee move trough the week. Doing a restore from a differential backup is easier then doing a restore from an incremental backup. To restore data from differential backup we have to restore data from the last full backup and then restore data from the last differential backup that we took.
Considerations
Remember that we should not combine incremental and differential backups. Also, if we need to restore data on a system which can not support data compression, we should turn of compression before we do our backup. Also, we could run into problems if we plan to restore our data to a different operating system. To get around that problem we should first restore our data on the same Windows and then copy or migrate our data to the different system. We must be a member of the Administrators or Backup Operators group to perform backups and restores. Backup Operators cannot view, edit, or delete files. Users with the appropriate backup permissions can back up and restore encrypted files. However, they will not be able to open and read those files.
Backup Example
Windows XP includes simple utility that we can use to backup our data and system files. To open Backup tool, go to Start > All Programs > Accessories > System Tools > Backup. The tool will open in wizard mode, but we can choose not to always start in wizard mode.
Image 268.1 – Backup or Restore Wizard
On the next screen we can choose to backup data or to restore data. In our case we will choose to backup data.
Image 268.2 – Back up or Restore
On the next screen we can choose what to backup. We can backup our documents and settings, everyone’s documents and settings, and all information on our computer. Also we can choose particular files and folders.
Image 268.3 – What to Back Up
In our case we will select the last option which will let us choose exactly which files to backup.
Image 268.4 – Selection
Notice that we can select particular files, folders or even the whole drives. Also notice that under My Computer, we can choose to backup System State. In our case we will only back up system state. On the next screen we can choose where to save our data.
Image 268.5 – Destination
In our case we will save our data to the C:\Backups folder and change the name of the file to SystemState.bkf. On the next screen we can choose to finish or take a look at some advanced options. Let’s click the Advanced button.
Image 268.6 – Advanced Options
On the first screen we can specify the type of backup that we want to perform, like Normal, Copy, Incremental, Differential or Daily backup. In our case we will select Normal backup and click Next. On the next screen we can select options like data verification, hardware compression or using volume shadow copy, if they are available.
Image 268.7 – Backup Options
On the next screen we can choose to append our backup to the existing backups or to replace them.
Image 268.8 – Append or Replace
On the next screen we can choose when to run our backup. Here we can create a schedule entry. In our case we will do our backup now. And that’s it, all options are set and our backup is ready to be performed.
Advanced Mode
To start Backup tool in advanced mode click on the Advanced Mode link on the first screen of the Backup Wizard.
Image 268.9 – Advanced Mode
To start a new backup we can go to the Backup tab, select what to back up, select our destination and then we can click on the Start backup button.
Image 268.10 – Backup Tab
Image 268.11 – Job Information
On the Job Information screen we can click on the Advanced button to set additional options.
Image 268.12 – Advanced Backup Options
These are the same options that we saw when we were in wizard mode. We can also schedule our backup to occur later or on regular intervals. Before we can do that we have to save our backup task. After that we have to provide credentials under which this task is going to run. We need to do this because backup might run when we are not logged on the computer. We also have to provide the Job name and set the dates on which we want our backup to occur. Setting this up is pretty straight forward process. This backup is going to be saved as a task which we can see in Control Panel under Scheduled Tasks.
Restore Data
To restore data, open the Backup tool and go to the Restore tab in advanced mode. Here we will see all backups that we performed before.
Image 268.13 – Restore Tab
Notice that we can choose specific data that we want to restore. We can choose to restore files to original location or we can choose some other location. When we click the Start Restore button, another window will appear on which we can go to advanced settings.
Image 268.14 – Advanced Restore Options
Remember
We can use the Backup tool to back up and to restore our data. We can start it in Wizard mode and in Advanced mode.
Paths that are mentioned in this article
- Start > All Programs > Accessories > System Tools > Backup – location of Backup tool