4. Restoring your data - considerations

4.1. Stop any backups while restoring.

If you are restoring any sizeable amount of data, you should disable any backups (scheduled or manual) from running until at least the restore has completed. Running a restore in conjunction with a backup will cause the two processes to slow considerably as they contend for your local machine's cpu and I/O bandwidth. Halting the backups also avoids the possible confusion of restored files being backed up and overwriting a previous version of a file backup. Once complete you should examine the files restored before reenabling any scheduled backups again.

Clearly certain circumstances which precede a large partition or system restoration cannot be planned. However, if you are planning a system or hardware upgrade which will leave your data at risk, there are methods by which we can minimise the number of tape volumes upon which the data is held. Please contact us in advance of such an operation at hfs@ox.ac.uk giving as much notice as possible of the planned upgrade and we will do what we can to help. Similarly, please let us know if you suffer a major disk failure and while you are waiting for a replacement, we may be able to help reduce the time needed for restore.

4.2. It may be quicker to restore from local software installation media

If you have the installation media for your software applications to hand, then it may well be quicker to re-install from these than restore from the HFS.

4.3. "I can't see old and/or deleted versions of a file in the restore window !"

You have just stumbled upon the difference between active and inactive files. An active file is a file for which a backup exists and the file currently resides on the local machine. An inactive file is a file for which a backup exists but which is no longer resident on the local machine. If you have overwritten or deleted a file or folder, and subsequently run a full incremental backup, TSM will mark the file or folder as inactive. At a subsequent restore, TSM displays by default, only active files in the Restore window. To display and restore your inactive files and folders using the TSM GUI, open the Restore window, select the View menu and check the [Display active/inactive files] option. Using the Command Line Interface add the -inactive option to your query. Please note that inactive objects are only kept on the TSM server - and hence can only be displayed - for a certain length of time after becoming inactive according to the backup policy. This policy information is available in our section on data retention.

4.4. Restoring complete partitions or filesystems

Restoring a complete data partition, with the exception of the 'root' or system partition, is as simple as restoring a single file or folder. Please see the sections headed 'Restoring Local Partitions' in the appropriate interface guide in the next section.

Restoration of the complete 'system' partition - i.e. the root partition on Linux machines, or the C: partition on Windows holds with it a number of complicating factors, not least the number of open system files that can or cannot be overwritten. Specific procedures need to be adopted for such a process to be successful. Necessarily, such procedures will be operating system (OS) platform specific - and will vary between OS releases. If you find yourself in a position of having to restore a system partition please contact us at hfs@ox.ac.uk for more help and advice.

It should be understood that the HFS/TSM does not support a full network re-install capability and that a combination of re-installation of the OS, basic network configuration, followed by installation and configuration of the TSM client will be required before restoring any necessary files from the HFS. Another consideration is that the hardware base may change following a major problem and/or the OS requirements may change. For all of these reasons we would recommend contacting us in these circumstances.

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