There is no problem in using Backup Express to augment an existing tape backup as long as you pay attention to a few points.
This is a technical article, intended for experienced I.T. Adminstrators.
Archive Bit Management. The archive bit, or 'A' bit, is a file system attribute which indicates to a backup program which files need to be backed up. The 'A' bit is set by Windows when a file is created or changed, and may be cleared by a backup program when the file is backed up. In this way, a backup program can easily determine which files are new or changed since the last backup.
Backup Express relies on the archive bit for performing its nightly incremental backups. If another backup program is operating on the same files, you must ensure that it does not alter the archive bit. The default behaviour of most backup programs, including the built-in Windows Backup (ntbackup.exe) is to clear the archive bit of files that are backed up. The result of this is that if the tape backup runs before Backup Express, Backup Express will find the archive bit on every file is clear, and will conclude that no files need to be backed up.
The tape backup program must be configured to not change the archive bit. In NTBackup you can do this by setting it to perform a 'copy' (rather than a 'normal') backup. This also means that you cannot use your tape backup program to perform differential or incremental backups.
Locked files. This is a minor issue, not a major concern. It may not be an issue at all under Windows 2003 or Windows XP. If the tape backup program attempts to backup a file while Backup Express has it open, or vice-versa, you may see an entry in the log that the file was skipped. The probability of this hapenning is very low.
Scheduling. It is preferable, though not essential, that the tape backup and Backup Express be configured to run at different times.
Last update: 05:36 PM Monday, November 16, 2009