Open Files and BackupAssist™

Overview

BackupAssist™ provides a basic level of open file backup protection by enhancing the functionality of NTBackup. It is able to backup all open files on Windows XP and 2003 Server, and also all open files that are not exclusively locked on Windows NT, 2000, XP and 2003.

This level of open file support is ideal and sufficient for many small and medium organizations, and BackupAssist™ provides a cost-effective way of delivering basic open files support.

This white paper explains how BackupAssist™ handles Open Files, through a simple example. It also explains how to restore Open Files.

BackupAssist™'s handling of open files varies based on the Windows Operating System version.

Two levels of Open File Support (OFS) are provided, and these are described in the following sections.

1. Full Support

On Windows XP and 2003, files on a local drive that are currently in use are backed up completely as if a "snapshot image" was taken at the time of the backup.

This is done through a feature known as volume shadow copy. This feature ensures data integrity and reliable backups.

2. Basic Support

Basic support - files that are in use are skipped by NTBackup during the backup. BackupAssist™ will detect these files, and attempt to copy them to a temporary directory, and perform the backup on that temporary directory.

Open files locked with a shared lock or no lock are successfully backed up via this method. Examples of these open files include Outlook .pst files.

However, exclusively locked files cannot be copied, and cannot be backed up. These are typically SQL Server or Exchange data files. (Exchange Server should be backed up via the Exchange Server backup facilities in BackupAssist™).

Under Windows XP and 2003, basic support is provided for all network drives (including those referenced by UNC naming - eg. \\server_name\share_name\

Under Windows 2000 and NT 4.0, basic support is provided for only network drives that are mapped as a drive letter.

To turn on Basic Open File Support, see the Options tab in the BackupAssist™ Administration Console.

Enabling Open File Support (exact screen varies depending on Windows OS and software version)

To enable basic open file support, tick the Re-attempt backup of open files checkbox.

BackupAssist™ backs up your data in two phases:

Phase One: Your selected drives and directories are backed up. Open files are skipped by NTBackup.

Phase Two: Any open files are copied and backed up, as well as additional data (Exchange Server, any add-on modules)

This process is unique to BackupAssist™, and extends the capabilities of Windows Backup (NTBackup). The following chapters explain how BackupAssist™ will backup open files, and how to restore your open files.

This following simple example illustrates how BackupAssist™ handles open files with Basic Open File support.

Example details

The following system has been used for this example:

                            Operating System: Windows NT 4.0 Server
                            Directory to backup: C:\TestDir
                            Open files in this directory:
                            C:\TestDir\Open file - shared lock.txt
                            (locked with a shared lock)
                            C:\TestDir\Open file - exclusive lock.txt
                            (locked with an exclusive lock)
                        

The contents of the directory is shown below. We opened two of these files (one with a shared lock, and another with an exclusive lock) to show how BackupAssist™ will handle these open files.

Files selected for backup

When BackupAssist™ first runs NTBackup to backup your files, all open files are skipped by NTBackup.

There are two open files in this directory, so we expect both files to be skipped. This is shown in the email report that's sent out by BackupAssist™. (See below)

BackupAssist™ will then attempt to copy the open files to the Open Files working directory. Only the shared lock file can be copied. The exclusively locked file cannot be copied, because the Windows Operating System prevents programs from accessing that file.

This is also summarized in the email report that's sent out by BackupAssist™.

Email report part 1

BackupAssist™ will try to copy the open files to the Open Files Working Directory, which has been set to:

                            C:\Program Files\BackupAssist\OpenFiles
                        

BackupAssist™ will then run NTBackup again, and backup files from the Open Files Working Directory.

Under that directory, BackupAssist™ recreate the full directory structure of the open files. The table below provides instructive examples of how this works:

This means that you can deduce the original location of an open file from its location in the Open Files Working Directory.

The email report (shown below) summarizes all the open files that could and couldn't be copied.

Email report part 2

To perform a restoration of open files, run NTBackup. On Windows NT, you should insert your tape into the tape drive; on Windows 2000 and later you should locate your tape from the Restore tab and insert it when prompted.

During the Phase One backup of c:\TestDir, only one file was closed (ie. not open) - Normal file.txt.

In the view of the tape (shown below), you can see that file is available on the tape. To restore, select that file and click the Restore button.

NTBackup restore view - phase one

During the Phase Two backup, the open files were copied to the Open Files Working Directory (in this case - c:\Program Files\BackupAssist\OpenFiles).

The file, Open file - shared lock.txt was copied, and as shown in the screenshot below, is available for restoration.

NTBackup restore view - phase two

The Windows XP and 2003 operating systems provide a capability known as Volume Shadow Copy - meaning that open files on local hard drives will be backed up during the Phase One Backup.

BackupAssist™ provides basic open file support for network drives on Windows XP and 2003.

BackupAssist™ provides a basic level of open file backup protection by enhancing the functionality of NTBackup. It is able to backup all open files on Windows XP and 2003 Server, and also all open files that are not exclusively locked on Windows NT, 2000, XP and 2003.

This level of open file support is ideal and sufficient for many small and medium organizations, and BackupAssist™ provides a cost-effective way of delivering basic open files support.

For full enterprise level open file protection, extra software such as Open File Manager (from St Bernard) is required. See http://www.stbernard.com for more details on Open File Manager.