6. Virtual mount points

Virtual mount points present nominated directories to TSM as if they were separate partitions, effectively creating sub-partitions within any existing partitions that you may have. Virtual mount points do not change your data or its arrangement in any way - your current partitions and disk arrangements are not altered. They cause TSM, however, to view your data differently.

There is an advantage in having such pseudo-partitions because, as mentioned in 3. Memory-efficient backup above, TSM deals with data one partition at a time: so, splitting data into smaller groups can greatly improve TSM performance. However, if you implement new virtual mount points after having already backed up your data, any data that is under a newly-created virtual mount point will need to be resent to the HFS, since TSM will regard it as being in a new partition.

For example, you might have a series of directories in your root partition called /data1, /data2 and /data3, where /data2 contains 3 million files and is causing TSM to struggle to complete backups in good time. You can split off /data2 from the rest of the root partition by making it into a virtual mount point.

As an option in TSM, virtual mount points only exist for Linux and Unix; however, a workaround to create virtual mount points exists for Windows machines also. If you need to create virtual mount points in Windows, please contact the HFS Team. If you are using Linux or Unix, you can set them up as follows.

6.1. Setting up virtual mount points using the graphical user interface

To set up virtual mount points in the graphical user interface, do as follows:
  1. Run dsmj as root.

  2. Click on Edit, then Client Preferences. The Preferences Editor window will appear, on the General Preferences section.

  3. From the list of tabs on the left, click on Backup. The options for Backup Preferences will appear.

  4. Under Virtual Mount Point, for each folder that you would like TSM to back up as if it were a separate file system, click on Add, locate the relevant folder, and click on OK. Repeat this as necessary for as many times as is required.

  5. Under Domain for Backup, check whether or not Backup all local file systems is ticked. If it is, proceed to the next step. If it is not, then you need each virtual mount point to be ticked in this section. To do this:
    • Click OK in the Backup Preferences window. This will take you back to the main TSM window.

    • Click on Edit, then Client Preferences. The Preferences Editor window will appear, on the General Preferences section.

    • From the list of tabs on the left, click on Backup. The options for Backup Preferences will appear.

    • The virtual mount points which you created should now be listed under Domain for Backup. Ensure that each one is ticked.

  6. Now click OK in the Backup Preferences window. This will take you back to the main TSM window.

  7. Now verify that your new virtual mount point(s) is/are set up correctly. The easiest way to do this is in the TSM graphical user interface, by attempting to perform a manual backup with your new settings, verifying that the folders nominated as virtual mount points appear in TSM as if they were separate partitions. For how to run a manual backup, please see our instructions for backup selected files and directories in Linux or Solaris.

  8. Lastly, if you use the automatic scheduled backups, you must now restart the TSM scheduler after making changes to your TSM configuration. If you do not do this then the change that you have made will not be honoured on the scheduled backups. Please see our instructions for restarting the scheduler on Linux or Solaris. Alternatively, restarting your machine will have the same effect as restarting the TSM scheduler.

6.2. Setting up virtual mount points by editing the TSM configuration file

To set up virtual mount points by editing the TSM configuration file, do as follows:

  1. Locate the TSM configuration file dsm.sys. The location can be looked up in our list of TSM Options Files.

  2. Add a line for each folder that is to become a mount point, of the form:

    virtualmountpoint /data
    Note that the added line(s) must not end in a forward slash.

  3. Save the TSM configuration file.

  4. Now open dsm.opt for editing. This is located in the same directory as dsm.sys. Check whether or not the setting for DOMAIN is is ALL-LOCAL. If it is, proceed to the next step. If it is not, then you need each virtual mount point to be listed as a separate domain. To do this, you can either have one long DOMAIN line with space-separated values, or multiple lines. So, for example, to set your backup domain to back up the root partition, /media and /data, you can put either

    DOMAIN / /media /data
    or
    DOMAIN /
    DOMAIN /media
    DOMAIN /data

  5. Now verify that your new virtual mount point(s) is/are set up correctly. The easiest way to do this is in the TSM graphical user interface, by attempting to perform a manual backup with your new settings, verifying that the folders nominated as virtual mount points appear in TSM as if they were separate partitions. For how to run a manual backup, please see our instructions for backup selected files and directories in Linux or Solaris.

  6. Lastly, if you use the automatic scheduled backups, you must now restart the TSM scheduler after making changes to your TSM configuration. If you do not do this then the change that you have made will not be honoured on the scheduled backups. Please see our instructions for restarting the scheduler on Linux or Solaris. Alternatively, restarting your machine will have the same effect as restarting the TSM scheduler.

Up: Contents Previous: 5. Zip up small files and exclude the originals from backup Next: 7. Repartition your file system