dump
ext2/ext3/ext4 filesystem backup utility
TLDR
Backup filesystem to file
SYNOPSIS
dump [options] filesystem
DESCRIPTION
dump creates backups of ext2/ext3/ext4 filesystems. It operates at the filesystem level, reading disk blocks directly, which provides complete backups including file metadata and special files.
Dump supports incremental backups through levels 0-9. Level 0 is a full backup; higher levels back up files changed since the last backup at a lower level. The /etc/dumpdates file tracks backup history.
PARAMETERS
-0 through -9
Dump level; 0 is full, 1-9 are incremental.-u
Update /etc/dumpdates after successful dump.-f file
Output file or device.-a
Auto-size; bypass tape length calculation.-h level
Honor nodump flag for levels above this.-L label
Label for dump volume.-z level
Compress output with zlib.-M
Multi-volume; prompt for new tape.
CONFIGURATION
/etc/dumpdates
Records dump history tracking dump levels and timestamps for incremental backup management./etc/fstab
Defines filesystem mount points that dump uses to identify filesystems by name rather than device.
DUMP LEVELS
Level 1: Files changed since level 0
Level 2: Files changed since level 1
...and so on
CAVEATS
Filesystem-specific; works with ext2/3/4 but not XFS or Btrfs. Cannot back up mounted filesystems reliably in all cases. Use restore command to recover files. Modern alternatives like rsync or borg may be preferred.
HISTORY
dump dates back to early Unix at Bell Labs in the 1970s. It was one of the original backup utilities, designed for tape backups. The Linux version (dump/restore) was adapted from 4.4BSD and continues the traditional interface while supporting modern ext filesystems.
