Performing a backup with limited bandwidth
If you plan to perform a backup over a network device that has limited bandwidth, such as a modem, you can help reduce network traffic by using adaptive subfile backup.
About this task
An adaptive subfile backup sends only changed portions of a file to the server during successive backup operations.
Perform the following steps to use adaptive subfile backup:
Procedure
- Ensure that the server allows this type of backup. Check with your system administrator.
- Set the subfilebackup, subfilecachepath and subfilecachesize options in your client options file dsm.opt. If you set the subfilebackup option to yes and no exclude.subfile statements exist, the backup-archive client considers all files for adaptive subfile backup processing.
- Add an exclude.dir option to your client options file, which excludes the directory containing the subfile cache information.
Results
When you are ready to back up changes, adaptive subfile backup occurs as part of incremental and selective backups.
You can restore an adaptive subfile backup using the restore command. The server restores the base file along with the updates from the changed (delta) subfile so that what you receive is the latest backed-up version of your file.