_               _               _                _                     _
 | |             | |             | |              | |                   | |
 | |__  _ __ ___ | | _____ ______| |__   __ _  ___| | ___   _ _ __   ___| |__
 | '_ \| '__/ _ \| |/ / _ \______| '_ \ / _` |/ __| |/ / | | | '_ \ / __| '_ \
 | |_) | | | (_) |   <  __/      | |_) | (_| | (__|   <| |_| | |_) |\__ \ | | |
 |_.__/|_|  \___/|_|\_\___|      |_.__/ \__,_|\___|_|\_\\__,_| .__(_)___/_| |_|
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broke-backup.sh was born out of necessity—sometimes you cannot afford to backup all of your data. The first thing that gets excluded from a backup is large, replaceable data such as Linux ISOs. ☠️

This script is meant to give a little bit of security to that replaceable data by recording the directory contents using a basic Unix command: tree. It will output these directory trees to a user-defined backup folder, and email monthly archived backups.

Familiarity with tree is not needed; this script takes care of the most common use-case. The core concept is that it recursively lists directory contents, and can be output to a text file. For advanced users, it has many custom options that can be found at its man page.

Disclaimer: Despite 'backup' being in the name, this will not protect your data. It will save a text-only list of files and directories, which amounts to being a disaster recovery assistant. If/when disaster strikes you might lose your files, but you will know exactly what you lost so you can replace the data.

Example Tree Output

This truncated example is a Calibre library folder set to a depth of 2 (Show the children of the Comics folder and their sub-folders; Alan Moore and Andrew Donkin). In this script, this text is output to Comics.txt

/path/to/Comics
├── Alan Moore
│   └── Watchmen (166)
├── Andrew Donkin
│   ├── Artemis Fowl (223)
│   ├── The Arctic Incident (224)
│   ├── The Eternity Code (226)
│   └── The Opal Deception (225)
...

Example Backup Folder

This is my personal backup folder, that has been running since October 2020, as of August 2021. It backs up 6 locations—14 TiB of 40k files—into a 4 MiB Backup directory. A single archived backup is ~60 KiB.

It keeps 14 days of live (uncompressed) backups, and archives monthly backups indefinitely.

Usage

Dependencies:

• tree

• mutt - must have a working configuration

• xz-utils

Configuration

There are 7 basic config settings:

• recipient_email - Recipient email address

• email_subject - The subject for sent emails

• monthly_email_body - The body of the monthly email

• forced_email_body - The body of the forced email

• output_dir - Output directory for backups

• SOURCES - List of directories to backup

• DEPTH - Depth settings for the above sources

Advanced Tree Settings

To accommodate advanced uses, specifying custom tree options per source is supported. Setting use_custom=TRUE will override the DEPTH settings of the basic config with CUSTOM_OPTIONS

Scheduling

broke-backup.sh is designed on a daily job schedule. It will also happily run less often, or purely on a manual basis.

Suggested config is to set a cron job to run the script daily. My personal config runs every day at 00:25

Logic Overview

The script has been written to be self-documented and should be fairly easy to follow but it's overall flow is:

• if today's backup already exists:
  • send a forced backup email—You may want this for two reasons:
    • You've just started using broke-backup.sh and want an off-location backup before the 1st of the month rolls around
    • Testing your configuration
• else run today's backup to the user-defined backup folder
  • if today is the 1st of the month;
    • send a monthly backup email; and
    • Archive a copy into the /Archives sub-directory as .tar.xz
• Delete backups older than 2 weeks

Current Limitations

• Two sources cannot have the same name

  • /example/media/path and /example/cloud/path will both output to path.txt—the second backup will overwrite the first

• File modification times of the backup will be fudged

  • When a backup job is finished, the directory will be backdated to 00:00 of the current day so the cleanup logic works consistently.