saf

"one backup is saf, two are safe, three are safer"

Current saf version is 0.16, saf requires Python 3.10 or newer

saf is a simple, reliable, rsync-based, battle tested, well rounded backup system, written in Python.

It uses rsync to incrementally back up your data to a different directory, hard disk or remote server via SSH. All operations are incremental, atomic and optionally possible to resume.

saf is using very limited set of commands in the background, so it plays well with storage shells with limited set of commands, like Hetzner Storage Box.

Main backup code is used in production for many years and has proved its reliability, while recent saf updates only improve user facing commands. No guarantees but should be safe to use.

Basic concepts

In saf every local file system directory can become backup source location. Each backup source location can have one or more backup target locations, in practice same directory (and its sub-directories) can be backed up to several target locations.

Each backup source location (initialised by saf init) contains .saf.conf file, which is a simple and easy to change configuration file in Python configparser format. It is easy to query backup source locations down the directory tree with saf status or saf status --all, or up the directory tree with saf status --reverse.

Each .saf.conf can contain one or more [<name>.target] sections, defining backup target locations. It is easy to add any number of different local or remote backup locations with saf init --name <backup-name> <target-location>, where target-location can be local directory /mnt/backup-disk/backup-path or remote storage/server my-server:/mnt/backup-disk/backup-path.

Every saf command is location relative. saf will find .saf.conf in current or any of the parent directories and perform requested command. First backup target is always considered default but all the commands can specify what target name they are referring to.

NOTE: Don't use relative paths to specify target location. Always specify full target location /home/user/backup instead of ./backup or ~/backup. Relative locations are user related and not suitable for backup target.

NOTE: Final slash / when specifying target location doesn't matter, saf will interpret location with or without slash correctly.

Every .saf.conf contains [exclude] section that uses standard rsync exclude syntax, so we can specify exclusions for each backup source.

Installation

Clone from github

git clone https://github.com/dusanx/saf

It is usually a good idea to put saf in path to be available on the command line, but it will work as good with specifying /full/path/to/saf on each invocation. Contibutors are welcome to create packages and send MR's for any specific OS or distribution.

Packages for Arch or Debian or Ubuntu or Mint or Fedora or Gentoo or ...

Contributors are welcome.

TL;DR usage

I want to create backup source point at my home folder, so I need to go there first:

cd ~

Initialize backup source and first local backup target (since we didn't specify --name, this target will be called B0):

saf init /mnt/backup_ssd/saf-backup/home

NOTE: Each saf command will require that backup.marker file exists at the destination and offer commands to create it if it is missing. This applies to any backup target, so saf can be sure that we can reach target location. In short just follow instructions when backup.marker related message appears.

Check and modify .saf.conf responsible for current folder:

saf status
saf configedit

Run the first backup (--name can specify target if there is more than one):

saf backup

Check the backups (--name can specify target if there is more than one):

saf list
saf realsizes

Add another target, this time over ssh on my-remote-server (specify target name too):

saf init --name my-vpn my-remote-server:/backup/saf-will-use-this/home

Add another target, this time on my Hetzner Storage Box (replace u000000 with actual Hetzner user ID):

saf init --name H0 u000000@u000000.your-storagebox.de:/home/backup/saf-backup

NOTE: Make sure to check and edit .saf.conf to get all the parameters right, for instance remote storage box can be using different port than usual port 22.

With single backup source and three different backup targets, we can issue any command without specifying --name (meaning saf will use first target in the list, in our case B0) or by specifying any of the B0, my-vpn, or H0 names:

saf list H0
saf realsizes my-vpn
saf backup my-vpn
saf rmrf H0 ./bin/zoom
saf backup # Note: this command will assume target B0 since it is the first target
saf freespace H0

NOTE: Every saf command is location relative. saf will find .saf.conf in current or any of the parent directories and perform command. First backup target is always considered default but all the commands can specify what target name they are referring to.

Commands

saf version [-h]

Print saf version.

saf init [-h] [--name taget-name] target

Initialize saf backup source at current folder and add first backup target or add backup target to already existing .saf.conf.

saf status [-h] [--all | --reverse]

Check status of the current directory, is it covered by any .saf.conf backup source. Add --all to check all the locations up to root folder, since current folder can be covered by many different source locations. Add --reverse to find all .saf.conf files recursively in all the sub-directories. --all and --reverse can't be used at the same time, they are searching in different directions.

saf configedit [-h] [--quiet | --verbose {0,1,2} | --debug]

Find and edit .saf.conf closest to current directory. This .saf.conf will be used for all the saf commands issued in current directory.

saf list [-h] [--quiet | --verbose {0,1,2} | --debug] [target-name]

List all the backups in the specific [target-name] or using defult one. Sorted by time and date, with markers showing keep-<period> difference, as specified in .saf.conf

saf realsizes [-h] [--quiet | --verbose {0,1,2} | --debug] [target-name]

Uses du to reach target location and check real folder sizes, since we are using rsync with hard links wherever possible.

saf freespace [-h] [--quiet | --verbose {0,1,2} | --debug] [target-name]

Checks free space left on the specified or default target location.

saf prune [-h] [--quiet | --verbose {0,1,2} | --debug] [target-name]

Prunes backups by criteria specifed in .saf.conf. Also executed automatically before each saf backup.

saf backup [-h] [--quiet | --verbose {0,1,2} | --debug] [--resume] [target-name] [local-path]

Runs the backup. It is probably a good idea to start it periodically for each backup target. Since saf is using current directory to determine what backup source and target to use, either cd to the desired directory before running backup or add desired local path as parameter so saf can cd there before backup.

Last optional parameter can specify local path, so saf can cd there before executing backup. If local-path is specified there is no need to use cd <location> && saf backup, saf backup B0 /home/user can be used instead. If local-path is specified, target-name must be specified too, even if it is the default target.

Example usage for the local user home directory, for the default backup target:

cd /home/user && saf backup

saf backup B0 /home/user

saf rmrf [-h] [--quiet | --verbose {0,1,2} | --debug] [target-name] path

It is not unusual that some big or unwanted files or folders slip into backups. To prevent their future appearance we can edit .saf.conf to exclude such files or directories. However, as they remain present and taking space in the existing backups, rmrf offers elegant way to remove them. For instance, if my H0 backup contains unwanted ~/bin/zoom, I can easily remove it everywhere with

cd /home/user && saf rmrf H0 ./bin/zoom

NOTE: Using relative paths in rmrf is going to work since all the paths are calculated from backup source location.

saf difference [-h] [--quiet | --verbose {0,1,2} | --debug] [target-name] backup

This command should compare backup with the previous one and detect differences. Currently works well with the local file system backup targets. Depending on the remote backup shell capabilities, maybe works with the remote targets if they have rsync command available.

saf revisions [-h] [--quiet | --verbose {0,1,2} | --debug] [target-name] path

Most useful for local backup storage use, saf revisions will list all the backup directories, scattered across all backups in local backup target, where specified path content differs.

saf revisions ~/Desktop

For the remote backup targets, this command is much more limited, listing all the possible locations for the requested path.

For the local backup targets, this command will list only those backups that contain requested folder content changes, so the list will both be short and only listing different/changed content.

List of revisions can be used to manually cd to any of the backups and compare with or restore to a specified directory.

File manager integration

Using saf revisions, every file manager can have full time-machine like restore, assuming that somebody writes appropriate plugin. Contributors are welcome.

Vifm

Vifm plugin is available at plugin/vifm.

Install Vifm plugin by copying or symlinking saf-revisions (plugin folder) to $VIFM/plugins/ (usually ~/.config/vifm/plugins/ or ~/.vifm/plugins/). This will make :Saf* commands available in Vifm:

:SafRevisionsToggle     -- Activate or deactivate saf-revisions
:SafRevisionsActivate   -- Turn saf-revisions on
:SafRevisionsDeactivate -- Turn saf-revisions off
:SafPreviousRevision    -- Starfield! Warp! Magic! Back in time.
:SafNextRevision        -- Starfield! Warp! Magic! Forward in time.

Map appropriate keys to saf-revisions plugin functions, pick any unused keys that work for you:

nnoremap @ :SafRevisionsToggle<cr>
nnoremap < :SafPreviousRevision<cr>
nnoremap > :SafNextRevision<cr>

Start Vifm, then in any folder backed up with saf to local file system backup target (reaching remote targets is not possible at the moment) execute :SafRevisionsToggle command, or with definitions like above press @. Navigate trough all the backups where folder content is changed with :SafPreviousRevision and :SafNextRevision functions or keys mapped to those functions. Switch back to normal with another :SafRevisionsToggle.

NOTE: Please keep in mind that you will be browsing actual backup folder content. Changing such content is possible but usually a bad idea. Limit interaction to review and copy content to backup source folder, not the other way around.

Contributing

Contributors are welcome. Code, documentation or packaging improvements are welcome.

Related projects

Thanks to laurent22/rsync-time-backup and cytopia/linux-timemachine for the inspiration.

Changelog

Changelog

License

MIT License