Windows Server Hack [Electronic resources] نسخه متنی

Hack 91 Back Up Individual Files from the Command Line

You can't back up individual
files using the ntbackup command, but there's a
workaround.

The normal syntax of the ntbackup command in Windows 2000
and Windows Server 2003 lets you select specific folders to back
up, but it doesn't let you select specific files.
For example, to back up your C:\data folder as
D:\backups\031105.bkf you would type the
following at the command line (where /j indicates
the descriptive name of the backup job and /f
means we're backing up to file instead of to tape):

ntbackup backup C:\data /j "Nov 5 2003 backup of Data folder" /f 
D:\backups\031105.bkf

But what if you want to back up an individual file in the
\data folder but not the entire folder? This is
easy to do using the GUI version of the Backup tool. Just start the
tool, switch to the Backup tab (click Advanced Mode when the wizard
starts in Windows Server 2003), expand the C:
drive, select the \data folder, and
check off the specific files you want to back up.

However, doing this from the command line presents a problem, because
the syntax of ntbackup doesn't
allow you to specify files. There is, however, a workaround: you can
specify the names of the specific files you want to back up in a
backup selection (*.bks) file (also called a
script selection file) and use the
@ symbol to specify this file in your
ntbackup command, as follows (where
filename.bks is your
backup selection file):

ntbackup backup @filename.bks /j "Nov 5 2003 backup of
 Data folder" /f D:\backups\031105.bkf

The problem is, you can't create a .bks
file from the command line; you have to do it from the
GUI.

Creating a .bks file

To create a .bks file using
the Backup utility, you simply create a
backup job with the selected files you want to back up and then save
the job without actually running it. Then, you can copy the
.bks file to another location and use
ntbackup to back up the files from the command
line.

For example, say the folder C:\data contains
three filesproducts.doc,
sales.doc, and
reports.docand you want to back up only
products.doc from the command line. Start the
Backup utility (switch from the wizard to advanced mode in Windows
Server 2003), expand the folder tree, and check the box beside
products.doc, as shown in Figure 10-1.

Figure 10-1. Using Backup to create a backup selection file

Now, simply select JobsSave Selections to create
your .bks file (specifying a filename like
onefile.bks), and close the Backup utility. By
default, any .bks files you create are stored in
your user profile in the C:\Documents and
Settings\username\Local Settings\Application Data\Microsoft\Windows
NT\NTBackup\Data folder. To see this hidden folder in
Windows Explorer, select ToolsFolder
OptionsView"Show
hidden files and folders."

When you open onefile.bks using Notepad, it
contains one line of text:

C:\data\products.doc

Now, copy onefile.bks to a directory with a
shorter path, like C:\BKS,
since you don't want to have to type
C\Documents and Settings\...\Data at the command
line. Now you can back up the single file
products.doc from the command line as follows:

ntbackup backup @C:\BKS\onefile.bks /j "Nov 5 2003 backup of Data folder" /f
 D:\backups031105.bkf

Make sure you don't forget the @ sign before your .bks file; if you do, the backup will fail without warning (a backup-job file will be created, but you won't be able to restore from it). Also, be sure to enter the absolute path for the .bks file, because relative paths aren't supported.

Hacking the .bks file

We've seen how easy it is to back up individual
files using ntbackup, by first using the GUI
Backup utility to create a .bks file. Once
you've created such a file, it's
easy to hack it using a text editor such as Notepad, because its
syntax is easy to understand. In fact, its syntax is so simple you
can simply create a .txt file containing the
right information and then rename it with a .bks
extension, instead of using Backup to create the
.bks file first. In other words, it gets even
easier!

Anyway, if we start with our existing file,
onefile.bks, and later
decide that we want to back up both the products.doc
and sales.doc files, all we need to
do is add a second line to the file, to make it read as follows:

C:\data\products.doc
C:\data\sales.doc

You can also use your .bks file to back up
entire folders or volumes by adding their paths to the file, as
follows (you should include the backslash at the end of your volume
or folder):

E:F:\budgets\

You can also back up the System State information on your server by
adding the following line (make sure there is no space between the
words System and State):

SystemState

You can also back up shared folders by specifying their UNC path:

\\SERVER7\Docs

You can even back up a subfolder within a share (again, note the
trailing backslash):

\\SERVER7\Docs\Latest\

Finally, you can back up a volume or folder and exclude certain files
or folders. For example, the following .bks file
backs up the entire C:\data folder with the
exception of products.doc:

C:\dataC:\data\products.doc /exclude

Creating and customizing .bks files this way
gives you a lot of flexibility for performing backups from the
command line. Unfortunately, neither the ntbackup
command nor .bks files support the use of
wildcards. Perhaps we'll see that support in
Longhorn (http://msdn.microsoft.com/longhorn/).