System Administration Guide: Advanced Administration

The root (/) File System Fills Up After You Back Up a File System

You back up a file system, and the root (/) file system fills up. Nothing is written to the media, and the ufsdump command prompts you to insert the second volume of media.

Reason Error Occurred 

How to Fix the Problem 

If you used an invalid destination device name with the -f option, the ufsdump command wrote to a file in the /dev directory of the root (/) file system, filling it up. For example, if you typed /dev/rmt/st0 instead of /dev/rmt/0, the backup file /dev/rmt/st0 was created on the disk rather than being sent to the tape drive.

Use the ls -tl command in the /dev directory to identify which file is newly created and abnormally large, and remove it.