TSM will by default back up the data on your local hard drive(s) and any locally-attached drives. However, for a variety of reasons, some files are excluded from backup as part of our Acceptable Use Policy. These files fall roughly into the following categories:

• System files that would, in the event of loss, be best restored from the installation CD/DVD.
• Files holding temporary or transient data which cannot be restored in a meaningful or useful state.
• Files that are themselves backups of data.
• Files holding copyrighted material.
• Files held open by another application.
• Files which cannot be restored due to operating system restrictions.

Generally, such files do not need to be backed up. After a complete system failure, an operating system is best reinstalled rather than restored from backup; programs, similarly, are best reinstalled from original media/re-downloaded. It is therefore a waste of resources to back up such files, and so both these types are excluded from backup on desktop/laptop machines. Certain other exclusion rules deal with files that are difficult or even impossible to back up (e.g. virtual machines). Individual user files - work, personal documents and so on - are not affected by these exclusions. The advantages of the exclusions are therefore as follows:

• Backups are less likely to fail - a common cause of backup failure is locked system files, but if system files are not backed up then this problem will in many cases cease to be an issue.
• Less data is sent during backup, using up fewer resources in terms of:
  • Backup duration - backups will run more quickly;
  • Quantity of data - with less data sent, users are less likely to hit the HFS daily backup limit; and the HFS will need to store less data.

A summary of these excluded files is as follows; please note that this is a rough list and that it is not exhaustive. An up-to-date full list can be obtained in your client software by one of the two following methods:

• Command line interface:
  

  dsmc q inclexcl

• Graphical interface:
  
  Click Backup to open the backup window. Browse through your files/folders found under Local on the left-hand side. Items marked with a barred red circle (no-entry sign) will not be backed up.