Windows operating systems

Open files

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Some files on your system might be in use when you try to back them up. These are called open files because they are locked by an application for its exclusive use.

It is not very common for files to be opened in locked mode. An application can open a file in this way to avoid other applications or users from reading or accessing the file, but it can prevent backup programs from reading the file for backup.

You might not always want to use the open file feature to back up open or locked files. Sometimes an application opens a file or group of files in this locked mode to prevent the access of these files in an inconsistent state.

To avoid the increase of processor usage when you create a volume snapshot for each backup, and on platforms where the open file feature is not available or is not in use, consider the following points:

  • If the file is unimportant or can be easily rebuilt (a temporary file for example), you might not care if the file is backed up, and might choose to exclude it.
  • If the file is important:
    • Ensure the file is closed before backing it up. If backups are run according to a schedule, use the preschedulecmd option to enter a command that closes the file. For example, if the open file is a database, issue a command to close the database. You can use the postschedulecmd option to restart the application that uses the file after the backup completes. If you are not using a schedule for the backup, close the application that uses the file before you start the backup.
    • The client can back up the file even if it is open and changes during the backup. This is only useful if the file is usable even if it changes during backup. To back up these files, assign a management class with dynamic or shared dynamic serialization.
Note: If open file support is not configured: While the client attempts to back up open files, this is not always possible. Some files are open exclusively for the application that opened them. If the client encounters such a file, it cannot read it for backup purposes. If you are aware of such file types in your environment, you should exclude them from backup to avoid seeing error messages in the log file.