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Personal Backup

© 2011, J. Rathlev, IEAP, Kiel University
 

Frequently asked questions



Compatibility with Windows Vista and Windows 7

The program runs on 32-bit and 64-bit systems

Installation: Under these operating systems, the rights of an administrator are required. Always use the executable setup (pb-setup-5.0.xxxx.exe) to install or update Personal Backup. This will ensure that there are no restrictions on running the program.
Automatic backups on logoff or on shutdown work on the above systems without any problems.


How to configure a backup task

Many users do not know which backup mode is best for their purposes. If you are not an experienced user, you should select the default options In separate files, Separate directory per driveand Copy so that no files are deleted at the destination (unless you selected the Synchronize option). Only those files will be overwritten that have a newer timestamp at source and the backup will always be an exact (although optionally compressed and/or encrypted) copy of all data (more).
The integrated Restore function of the program can be used to restore your data.

The options Full, Differential and Incremental should only be used by experienced users if they want to perform a special backup strategy. In each case the destination directory is cleared before backup. Restore is only possible with a combination of full and differential or full and incremental backups.

Saving to zip files

There are two options for saving data as zip files:

  1. As one large zip file containing all subfolders: the original directory structure is contained within the zip file.
  2. As separate zip files for each subfolder: the destination directory structure is an exact copy of the original tree and each subfolder is a zip file containing all the files within the original subfolder.

Zipped backup files must always be written anew, so this option is not suited to a daily backup of large amounts of data. It is more appropriate for small amounts of data (e.g. special projects). Many programs (including Windows Explorer since XP) can read and unpack these files. To document the various stages of a project, you can use one of the optional placeholders as part of the filename.


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Notes on backup modes

There are four different backup modes:

Note:

The Differential and Incremental modes should always be used in combination with a Full backup, for example as follows:

  1. On the first day, make a full backup to directory A.
  2. On subsequent days, make a differential or incremental backup to directories B, C, etc.
  3. To restore your data:
    1. Full + differential: restore the last differential backup (e.g. E) and the last full backup (A).
    2. Full + incremental: restore all incremental backups (e.g. E, D, C and B) in reverse order and the last full backup (A).
    Already-restored files must not be overwritten during this.

Automatic backup schedules of this kind are controlled by the program.


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Backups to external drives (USB flash drives and HDDs)

When using such drives it can happen that the system does not always assign the same drive letter. To backup data always to the same medium independently of the drive letter, you can use the volume name of the removable media (:<volumename>:) instead. Go to Windows Start, Computer or Workplace, right click on the drive and select Properties to define a volume name.
Example:

Assign the name Backup-1 to the external drive.
Enter :Backup-1:\Backup instead of K:\Backup in Personal Backup

Disconnect drive

To disconnect the external drive automatically after backup, use the "External programs" function to start a small batch file which calls the utility program RemoveDrive.

Sample script:
rem remove external drive (RemoveDrive.bat)
RemoveDrive "Backup-1"

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How to use network resources

The destination directory may be located on any network device or computer. There are various ways to connect:


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Timeout on copying files

Since Version 5.0.5, a monitor has been incorporated to prevent the program from hanging (e.g. if the network connection is lost). If while copying files there is no response for a specified time (default: 30s), the process will be canceled. The timeout is adjustable in Task settings ⇒ More options. Setting it to zero disables monitoring (view How-to-video).


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Warning in log file: Timestamp could not be set

After a file has been successfully copied, its timestamp (date and time of last change) will be set to the value of the original file. If this doesn't happen, a warning will appear in the log file. This is only an indication of a problem, in that the actual backup of the file nevertheless occurred.
When backing up to a local or Windows network drive, this warning points to a problem in the destination directory (e.g. lack of administration rights) that should be investigated. Should this warning appear when backing up via FTP, the cause will probably be due to the fact that some FTP servers in principle offer no way to set the timestamp. In this case the warning can be ignored.


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Problems while copying to USB drives and NAS systems

When using a backup destination on one of the above devices, the backup might stop with the error message The destination volume is full! even if sufficient space is actually available. In this case you should reduce the size of the internal copy buffer (e.g. to 64 kB) via Task settings ⇒ Other task settings. Try different values to determine which size is optimal for your backup device.


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Starting the program from a USB flash drive

It is possible to configure Personal Backup in such a way that it can be started from a USB stick or drive without leaving traces on the host PC (Version 4.1.3.2 and above). Copy all files from the program directory (usually C:\Program Files\Personal Backup x) or the downloadable zip file to a directory on the USB drive (e.g. K:\PersBack), and use the command line options /ini:[IniFile] and /taskdir:[Directory] to start the program. The options set the program to use an ini file and a task directory on the USB drive.

Then, using a text editor, create a batch file (e.g. startpb.cmd) in the root directory of the USB drive with the following lines:

   @echo off
   echo Start Personal Backup from USB flash drive
   start PersBack\PersBackup.exe /i:%%progpath%%\pb.ini /t:%%progpath%%\

Start the program from the USB drive using this batch file and configure your backup task. To use a backup target directory on the USB drive itself, omit the the drive letter from the destination path (e.g. \Backup).


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Backups on logoff or shutdown

There are several methods to start a backup on logoff:


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The backup does not start on logoff or shutdown

If the backup does not start when logging off or shutting down the computer, the reason is usually an incorrect Windows setting. The registry key HKEY_CURRENT_USER\Control Panel\Desktop\AutoEndTasks determines whether running processes end automatically or not (see the information from Microsoft). This value must be "0" to allow a backup.
If the program XP-Antispy is installed, the value can also be changed from there: switch off the option Activate fast shutdown.


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The program starts slowly because at first, directories are scanned

On starting the program, the first directory of a backup task will normally be scanned for new files. If for example this is a whole partition, it can take a very long time.
There are two ways to get around this:

  1. Instead of having one large directory in the backup task, you can enter all its subdirectories and move the smallest to the top. Consequently, while you will have a little more work to do during configuration, at the same time you will have more opportunity to filter certain file types, individual files and directories out of the backup task, because such settings are selected separately for each directory in the task.
  2. You can disable the scanning of directories on starting in the main menu under Preferences ⇒ Program start ⇒ Scan directories. This will then be carried out only after clicking on one of the directories to be backed up.

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How the encryption works

Files are encrypted using the AES method, with the same routines as in WinZip (Info at WinZip and at Brian Gladman). The file format created depends on the backup mode:

No compression (proprietary file format):
Data is written to file in the same way as is done with zip but without prior compression (more info). As this is a non standard format, a restore can only be made with the internal function of the program.
   Enc-Header : 10, 14 or 18 bytes (depending on the length of the password)
                Salt value (8, 12 or 16 bytes) + password verification value (2 bytes)
   Enc-Data   : Same number of bytes as original file
   Enc-Trailer: 10 bytes Authentication code
   
With compression (modified gzip format):
Data is first compressed using the gzip algorithm and encrypted in the same way as described above. The encrypted data has its own verification, so the gzip checksum is always set to 0. The gzip file format is specified in RFC1952. Bear in mind that this standard does not contain recommendations for encryption. The format described below just follows its specifications. For a restore, the internal function of the program is required.
   Gzip-Header : 10 bytes
                 new: Flag byte: bit 5 = encrypted
   Enc-Header  : 10, 14 or 18 bytes (depending on the length of the password, see 1.)
   Enc-Data    : Same number of bytes as compressed original file
   Enc-Trailer : 10 bytes  (see 1.)
   Gzip-Trailer: 8 bytes
                 Crc always = 0
   
Zip file (compatible with zip standard):
A description of the zip format can be found at PkWare and notes on encryption at WinZip. Personal Backup creates WinZip-compatible encrypted archives. For restore, any compression program supporting these specifications can be used.

See program sources (in German) for more details.


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Unpacking gz and zip archives created on backup

If the backup target is inside a Windows directory (local, external or network) you can use the internal Restore function for unpacking. This works also with encrypted gz and zip files.
If the backup is on an FTP server, it is not possible to unpack gz and zip files directly. You have to copy them first into a local temporary directory using the internal Restore function or any FTP client (e.g. FileZilla). Then you can use the internal Restore function (see above) to unpack them to their final destination.


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Recovering corrupted zip files

In a zip archive, first of all the compressed files are saved with a header and checksum in the destination file followed by a directory with pointers the start of each file. See PkWare for more details.

If the directory is corrupted or missing, the zip file can then no longer be read by many programs, although the data itself may still be intact. Some archive programs (e.g. iZArc) provide tools to repair such files.

To be able at least partially to restore data from corrupted zip files created with Personal Backup, you can use the following program:


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Is the program capable of backing up system data?

The intended purpose of the program is to backup personal data such as documents, spreadsheets, images, etc., the loss of which can have a serious impact since the data is either impossible to recreate or can be achieved only after extremely time-consuming labor.

On the other hand, the operating system and applications in use can always be reinstalled from their original sources and while this will take some time, it is at least possible.

Saving this data with Personal Backup does not make sense because a restore is simply not possible. Moreover a daily backup of a running system is not necessary (in contrast to personal data). The fastest way to recover after a system crash is to restore the whole partition previously saved with an imaging tool. A freeware version for personal use is available from Paragon: Backup & Recovery Free Edition


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"Path too long" error in log file

The Windows API functions used in Version 4 of this program restrict the path length (directory + filename) to 260 characters (see Windows SDK). Even Windows Explorer in XP has this limitation.
Version 5 was built with Delphi 2009 which has full Unicode support. With this version, path lengths up to 32,000 characters are allowed.

With Version 4 you can use a workaround using the command "Subst":
Example:
The files to be backed up are located in the directory C:\Dir1\..\Dir2\Dir3\..\Dir4. The whole path (directory + filename) exceeds 260 characters.
To split the path, type at the DOS prompt:

subst X: C:\Dir1\..\Dir2
Now you have a new (virtual) drive X: with the subdirectory Dir3\... Add this to your backup task.
Later you can delete the assignment:
subst X: /d

To automate this procedure, start the following batch files before and after backup using the integrated function to execute external programs: SplitDir.cmd:

rem Split directory path and substitute with drive 
subst X: %1
UnsplitDir.cmd:
rem release substitution
subst X: /d
Execute before Backup:
SplitDir.cmd C:\Dir1\..\Dir2
Execute after Backup:
UnsplitDir.cmd


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The PC doesn't power off after backup

When performing a backup on shutting the computer down, it may be that the PC does not power off or does not restart.
The reason is that the Windows API function that notifies all programs before shut down (See "WM_QUERYENDSESSION" in Windows SDK) says nothing about the intended action (shut down or restart). To tell Personal Backup what to do after backing up, select this in the main menu Preferences ⇒ Shutdown.
An alternative method is to use the functions in the context menu called by right-clicking the icon in the Windows notification area.

Logoff script

This problem can be avoided by not using the integrated function Backup on logoff, but instead using a logoff (or shutdown) script. Create the following script and set the Windows policy for logoff (administrator rights are required):

  1. Create script file:
    1. Open Notepad or any other text editor.
    2. Insert this line:
      "%programfiles%\Personal Backup 5\PersBackup.exe" /force /hide <Backuptask>
      <Backuptask> is the full path of the configured backup task to be performed on logoff.
    3. If you have other backup tasks to do, add similar lines. Store the text file as LogOff.cmd in the folder
      C:\WINDOWS\system32\GroupPolicy\User\Scripts\Logoff\.
  2. Start ⇒ Run and start the Group Policy Editor gpedit.msc (not available in all Windows versions)
  3. Expand the tree:
    Policies for Local Computer ⇒ User Configuration ⇒ Windows Settings
  4. At Scripts, double-click Logoff.
  5. Click Add a Script and then the Browse.. button to select the file you just created. Close the window with OK.
  6. Close the group policy editor.

Note: To use a shutdown script instead, select the section Computer configuration in the Group Policy Editor. This requires at least Personal Backup version 5.2.


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Start Personal Backup as a service

The easiest way to start Personal Backup as a service is to use the Windows Task Scheduler. You can configure many different backup tasks to start at different times (e.g. on particular days of the week).
Process the following steps:

  1. Configure and save the backup task using the Personal Backup main window.
  2. Select the Windows Scheduler tab and start the wizard New backup as scheduled task:
    The current backup task will be taken over and the necessary command line options automatically inserted.
  3. Configure the time schedule
  4. Specify the user account with password under which the program is to be run.
Detailed description


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The scheduled task wizard requires a password

The wizard uses an interface to Windows Task Scheduler 1.0 that requires an account with password, so users working with an account without password cannot configure a scheduled task using the wizard. They must either add a password to their accounts or create a special backup account with password.
Note: Windows 7 uses Task Scheduler 2.0 that can start tasks without a password. Because the program libraries used in Personal Backup do not yet support this version, you will always need a password to create a scheduled task with the wizard. In any case you can configure a scheduled backup directly using the Windows Task Scheduler dialog.


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Where to find the ini file (program settings) and the log file

All program settings including the configuration of automatic backup tasks are saved in an ini file (Persbackup.ini). This is a text file and can be read with any text editor. Editing this file is, however, not recommended.
The ini file and the standard log file (Persbackup.log) are located in the user's application data directory. You will find this at the following locations:

Note: By default this directory is hidden. To make it visible, change the Windows Explorer setting via Tools ⇒ Folder Options ⇒ View ⇒ Show hidden files and folders.


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Saving Outlook files

The files used by outlook are locked for other applications and backing up this data requires that Outlook is not running

There are two ways to ensure this:

  1. Start automatic backup on logoff within the program or via a logoff script: at this time Outlook will have been terminated.
  2. Stop Outlook while the backup is running: you will need to execute scripts before and after backing up.

VB scripts to stop and restart Outlook

Using the function Execute external programs: before backing up, a script is run to stop Outlook and another script run to restart it as soon as the backup is completed. The following sample scripts can be modified for other applications. To create and edit the scripts you need a simple text editor such as Notepad. Save the scripts at an appropriate location using the proposed names. Click Edit at Options/Extended/External programs and insert the following command lines:
Before backup: %sysdir%\cscript.exe "<path>\StopOutlook.vbs"
After backup: %sysdir%\cscript.exe "<path>\StartOutlook.vbs"
and select the checkboxes.

Stop Outlook (StopOutlook.vbs):
  ' VB Script Document
  option explicit
  
  dim oWmi, sWmiO, oQResult, oProcess, WshShell, iRet
  
  ' Terminate Outlook 
  
  Set oWmi = GetObject("winmgmts:")
  sWmio = "select * from Win32_Process where name='outlook.exe'"
  Set oQResult = oWmi.Execquery(sWmio)
    For Each oProcess In oQResult
      iRet = oProcess.Terminate(1)
    Next
  Set oWmi = Nothing
  
  set WshShell = WScript.CreateObject("WScript.Shell")
  WScript.Sleep 100
Restart Outlook (StartOutlook.vbs):
  ' VB Script Document
  option explicit
  
  dim WshShell
  
  ' Start Outlook
  
  Set WshShell = WScript.CreateObject("WScript.Shell")
  
  ' The following line depends on the installed Office version
  WshShell.Run """%ProgramFiles%\Microsoft Office\Office11\Outlook.exe""", 9
Download the script files

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Personal Backup and Windows 98

Personal Backup Version 5 does not work under Windows 98. Users using this operating system must use Version 4.5!