Windows operating systems

Examples: Restoring large amounts of data

If you need to restore a large number of files, you get faster performance using the command line interface rather than the GUI interface. In addition, you improve performance if you enter multiple restore commands at one time.

About this task

For example, to restore all the files in your c: file space, enter:
   dsmc restore c:\* -subdir=yes -replace=all -tapeprompt=no
However, if you enter multiple commands for the root directories in your c: file space, you can restore the files faster. For example, enter these commands:
   dsmc restore c:\users\ -subdir=yes -replace=all -tapeprompt=no
   dsmc restore c:\data1\ -subdir=yes -replace=all -tapeprompt=no
   dsmc restore c:\data2\ -subdir=yes -replace=all -tapeprompt=no
Or, if you need to restore files for multiple drives, enter these commands:
   dsmc restore c:\* -subdir=yes -replace=all -tapeprompt=no
   dsmc restore d:\* -subdir=yes -replace=all -tapeprompt=no
   dsmc restore e:\* -subdir=yes -replace=all -tapeprompt=no
You can also use the quiet option with the restore command to save processing time. However, you will not receive informational messages for individual files.
Note: If you already have the appropriate values set for the subdir, replace, tapeprompt, and quiet options in your client options file, it is not necessary to include these options in the commands.

When you enter multiple commands to restore your files, you must specify a unique part of the file space in each restore command. Do not use any overlapping file specifications in the commands.

To display a list of the root directories in a file space, use the query backup command. For example:
   dsmc query backup -dirsonly -subdir=no c:\

As a general rule, you can enter two to four restore commands at one time. The maximum number you can run at one time without degrading performance depends on factors such as network utilization and how much memory you have. For example, if \users and \data1 are on the same tape, the restore for \data1 must wait until the restore for \users is complete. However, if \data2 is on a different tape, and there are at least two tape drives available, the restore for \data2 can begin at the same time as the restore for \users.

The speed at which you can restore the files also depends upon how many tape drives are available and whether your administrator is using collocation to keep file spaces assigned to as few volumes as possible. If your administrator is using collocation, the number of sequential access media mounts required for restore operations is also reduced.