dump

ext2/ext3/ext4 filesystem backup utility

TLDR

Backup filesystem to file

$ dump -0uf [/backup/root.dump] [/dev/sda1]

Backup with compression

$ dump -0uf - [/] | gzip > [backup.dump.gz]

Incremental backup (level 1)

$ dump -1uf [/backup/root.1.dump] [/]

Backup to tape device

$ dump -0uf [/dev/st0] [/home]

List files in dump archive (using restore)

$ restore -tf [backup.dump]

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 0: Full backup (all files)
Level 1: Files changed since level 0
Level 2: Files changed since level 1
...and so on

Common strategy: Weekly level 0, daily level 1.

INSTALL

sudo apt install dump

sudo dnf install dump

sudo zypper install dump

nix profile install nixpkgs#dump

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.