System Administration Guide: Devices and File Systems

Choosing the Type of Backup

You can perform full or incremental backups by using the ufsdump command. You can create a temporary image of a file system by using the fssnap command. The following table lists the differences between these types of backup procedures.

Table 24–4 Differences Between Types of Backups

Backup Type 





Copies a complete file system or directory

All data is in one place 

Requires large numbers of backup tapes that take a long time to write. Takes longer to retrieve individual files because the drive has to move sequentially to the point on the tape where the file is located. You might have to search multiple tapes. 


Creates a temporary image of a file system 

System can be in multiuser mode 

System performance might degrade while the snapshot is created. 


Copies only those files in the specified file system that have changed since a previous backup

Easier to retrieve small changes in file systems 

Finding which incremental tape contains a file can take time. You might have to go back to the last full backup.