Backup of Open Files

Since workstations and servers can have any number of open files during backups, these files might cause backup errors. Backup of Open files can be classified as:

• Successful
• Failed to backup
• Backed up with potential integrity problems.

Depending on the type of open file and operating system of the server/workstation, steps can be taken to reduce or eliminate the problems with Open Files Backup.

Open File Backup Strategy Options

Each backup set is configured (Backup Set Properties > Options) with a strategy to handle open files. Unless altered, the default setting will apply (Setup > Configuration > Defaults).

If DS-Client encounters an open file during the backup process, it will deal with it as prescribed in the strategies below:

If the backup of an open file fails on the first attempt, the DS-Client can be instructed to retry up to ten times.

NOTE: Even with the Open File Backup Strategy options, files that are completely locked will not be accessible (they will fail to be backed up with errors). However, these files can be accessed by using the VSS backup set option. Once DS-Client can read the file, it can be backed up.

VSS (Volume Shadow Copy Service)

The DS-Client will fail to backup files that are completely locked (i.e. files opened with deny read/write). Even if open files are backed up, those files may have potential integrity problems (as described above).

If you have to back up locked files, then you can use the Backup through volume shadow copies File system backup set option. Windows operating systems support VSS, which is a Windows feature that DS-Client can use to create an exact copy of the files, including all open files.

• VSS is configured from Backup Set Properties > Advanced Options (for Windows servers that have the service available).
• If configured, DS-Client will initiate a VSS snapshot for the specified computer (for any local volumes included in the backup) and perform the backup from the VSS snapshot.
• If the VSS snapshot fails, DS-Client tries to backup like a File system backup set (where the Open File strategy will apply).

For more information about VSS, refer to the corresponding Windows Help.

Conclusion

To reduce problems caused by backup of open files:

• Perform scheduled backups during off-peak hours.
• Perform special file backups for appropriate backup types.
• Exclude system and irrelevant files to eliminate unnecessary errors.