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Examples: Command line restores for large amounts of data

If you need to restore a large number of files, you can get faster performance by using the restore command instead of the GUI. In addition, you can improve performance by entering multiple restore commands at one time.

For example, to restore all the files in your /home file system, enter:
   dsmc restore /home/ -subdir=yes -replace=all -tapeprompt=no

However, if you enter multiple commands for the directories in the /home file space, you can restore the files faster.

For example, you could enter these commands:
   dsmc restore /home/monnett/ -subdir=yes -replace=all -tapeprompt=no
   dsmc restore /home/gillis/ -subdir=yes -replace=all -tapeprompt=no
   dsmc restore /home/stewart/ -subdir=yes -replace=all -tapeprompt=no

You can also use the quiet option with the restore commands 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 user-options file, you do not need to include those 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. Be sure you do not use any overlapping file specifications in the commands.

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

As a general rule, you can enter from 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 how much memory you have and network utilization.

The speed at which you can restore the files also depends on how many tape drives are available on the server, and whether your administrator is using collocation to keep file spaces assigned to as few volumes as possible.

For example, if /Users/user1 and /Users/user2 are on the same tape, the restore for /Users/user2 must wait until the restore for /Users/user1 is complete. However, if /Users/user3 is on a different tape, and there are at least two tape drives available, the restore for /Users/user3 can begin at the same time as the restore for /Users/user1.

Set the system ulimit values to unlimited (-1) if you are restoring very large (2 GB) files with HSM or the backup-archive client. The Tivoli® Storage Manager client can restore these large files with enough system resources. If the ulimits are set to lower values, there might be restore failures.