Embarassingly simple backup solution.
You want to have a backup of your data, trust me. Maybe you don't need it now, but you still want to have it. Just in case.
Now that you have a backup on a separate drive inside your PC, and another one on a disconnected drive stored securely in the corner of your desk, you start looking for a more... distributed solution. What you want is an off-site backup. As it happens, you have a server with SSH access just sitting over there, doing nothing, and you have some spare GBs on it.
This is exactly the scenario in which this repository becomes useful. It is the most bare-bones off-site backup script you will probably find.
Pros:
- encrypted using GPG
- written in BASH so runs on pretty much anything
- uses SSH for transport between local machine and remote storage server
- performs rudimentary deduplication and compression
Cons:
- written in BASH so it has the usual quirks of BASH scripts
- uses SSH for transport so is kinda slow
- performs only rudimentary deduplication so your archive size roughly equals the real size of your data
Be warned that it is a prototype! I wrote it to diversify my backups and published it in hope that it may be useful for other people, but I cannot in good faith say that this is a rock solid software and will not fail. Use at your own risk.
AND ALWAYS HAVE UP-TO-DATE BACKUP IN AT LEAST TWO LOCATIONS!
Put this in ~/.backup.config file:
# Fingerprint of GPG key used to encrypt the backup.
gpg_key=ABC012DEADBEEFC0FFEE
# The script needs to know where to upload blocks and indexes.
storage_user=john.doe
storage_host=example.com
storage_root=/home/backup/johndoe
On the remote machine, in the storage_root directory you must create two subdirectories: blocks and
indexes.
To create the backup use:
]$ cd ~
]$ B3_ARCHIVE_NAME=stuff create.sh ./Important/Stuff
To restore the backup use:
]$ cd ~
# First operand is the name of the backup, and
# the second is the timestamp of that backup you want to
# restore.
]$ restore-remote.sh stuff 20171012T232347
The basic idea is to create a big tar archive split into 128K blocks of encrypted data, deduplicate and compress it, and ship it off to some server.
This program is written in such a way that it never sees a full tar file; it is always piping data, so the "working size" should not exceed a few megabytes for blocks. It needs, however, to have a full archive index available during both the creation of the backup (to store the order of blocks), and the restoration of the backup (to know which blocks should be fetched and extracted).
While blocks should always be roughly ~128K in size, indexes can grow big. The size of the index is about 1 byte for every 1KB of backup data (before encryption, compression, and deduplication). Blocks of data are identified by their SHA512 sums. SHA512 has the convenient property that its hex digests are 128 bytes long, and map nicely to the 128KB block size.
When creating a backup:
{local machine} -> tar -> split -> SHA512 -> gzip -> GPG -> scp -> {remote machine}
When restoring a backup:
{remote machine} -> scp -> GPG -> gzip -> tar -> {local machine}
This is Free Software published under GNU GPL v3 or any later version of this license.