Borg Backup

(a fork of Attic)

"The holy grail of backup software"

Thomas Waldmann @ shackday 2015

Feature Set (1)

• simple & fast
• deduplication
• compression

• authenticated encryption

• easy pruning of old backups

• simple backend (k/v, fs, via ssh)

Feature Set (2)

• FOSS (BSD license)

• good docs

• good platform / arch support

• xattr / acl support

• FUSE support ("mount a backup")

Code

• 91% Python3 + Cython
  (high-level code, glue code)
• 9% C
  (performance critical stuff)
• only ~6000 LOC total
• few dependencies
• unit tests, CI

Security

• Signatures / Authentication
  no undetected corruption/tampering
   
• Encryption / Confidentiality
  only you have access to your data
   
• FOSS in Python
  review possible, no buffer overflows

Safety

• Robustness
  (by append-only design, transactions)
   
• Checkpoints
  every 5 minutes (between files)
   
• msgpack with "limited" Unpacker
  (no memory DoS)

Crypto Keys

• client-side meta+data encryption
   
• separate keys for sep. concerns
   
• passphrase pbkdf2 100k rounds
   
• Keys:
  • none
  • repokey (replaces: passphrase-only)
  • passphrase protected keyfile

Crypto Cipher/MAC

• AEAD, Encrypt-then-MAC
  • AES256-GCM / GHASH (exp.)
  • AES256-CTR + HMAC-SHAxxx
  • Counter / IV deterministic, never repeats
     
• uses OpenSSL
  
   
• Intel/AMD: AES-NI, PCLMULQDQ

Compression

• none
  • no compression, 1:1 pass through, no cpu usage
• lz4
  • low compression, super fast
  • sometimes faster than w/o compression
• zlib
  • medium compression, medium fast, level 0..9
• lzma
  • high compression, slow, level 0..9

Deduplication (1)

• No problem with:
  • VM images (sparse file support)
  • (physical) disk images
  • renamed huge directories/trees
  • inner deduplication of data set
  • historical deduplication
  • deduplication between different machines

Deduplication (2)

• Content defined chunking:
  • "buzhash" rolling hash
  • cut data when hash has specific bit pattern,
    yields chunks with 2^n bits target size
  • n + other chunker params configurable now
  • seeded, to avoid fingerprinting chunk lengths
     
• Store chunks under id into store:
  • id = HASH(chunk)
  • id = MAC(mac_key, chunk)

Borg, the present

• Borg Backup is a fork of Attic:

  • currently tracking attic dev.

  • plus a lot of conservative PRs
    (stuff from attic/merge branch "merge")

  • bug and scalability fixes

  • plus a lot of new stuff in "experimental" branch ("exp.")

  • not compatible to Attic

Borg, what's different?

• developed by "The Borg Collective"

• more open development

• new developers are welcome!

• quicker development

• redesign where needed

• changes, new features

• incompatible changes with good reason

• thus: less "sta(b)le"

Borg, the future

• scalability improvements

• speed improvements

• architectural changes

• pull backups? backup-only mode?

• better logging / exception handling

• more backends? http / ftp / aws / google / ...

• other platforms / architectures

• BorgWeb GUI (for daily user needs)

• <you name it>

Borg - you can be assimilated!

• test scalability / reliability / security

• be careful!

• file bugs

• file feature requests

• improve docs

• contribute code

• spread the word

• create dist packages

• care for misc. platforms

Borg Backup - Links

borgbackup.github.io
 

#borgbackup on chat.freenode.net

Questions / Feedback?

• Just grab me at the conference!

• Thomas J Waldmann @ twitter

Borg - Demo

I'll show borgbackup using the

"all inclusive" binary.

You could also use:

Source code checkout from github

Release packages from PyPi

Linux / BSD / ... packages

install

# download the binary and the gpg signature.

...

# verify the gpg signature

gpg --verify borgbackup-linux64.asc


# install / fix permissions

cp borg-linux64 /usr/local/bin/borg
chmod 755 /usr/local/bin/borg
chown root.root /usr/local/bin/borg

init / create

# initialize a repository:

borg init /tmp/borg


# create a "first" archive inside this repo (verbose): 

borg create --stats /tmp/borg::first ~/Desktop


# create a "second" archive (less verbose):

borg create /tmp/borg::second ~/Desktop


# even more verbose:

borg create -v --stats /tmp/borg::third ~/Desktop

list / extract / check

# list repo / archive contents:

borg list /tmp/borg
borg list /tmp/borg::first

# extract ("restore") from an archive to cwd:

mkdir test ; cd test
borg extract /tmp/borg::third

# simulate extraction (good test):

borg extract -v --dry-run /tmp/borg::third

# check consistency of repo:

borg check /tmp/borg

info / delete / help

# info about archive:

borg info /tmp/borg::first

# delete archive:

borg delete /tmp/borg::first

# delete repo:

borg delete /tmp/borg

encrypted repo

# options, options, options, ...

borg init --help

# create a encrypted repo
# (pw protected key file stored locally)

borg init -e keyfile /tmp/borg-enc

# create a encrypted repo
# (pw-protected key file stored in repo):

borg init -e keyfile /tmp/borg-enc


# ... (same as before, but you need to give passphrase)

remote via ssh

# connect to remote borg via ssh:
# remote borg needs to be compatible with local

borg init ssh://user@host:22/mnt/backup/borg

borg create ssh://user@host:22/mnt/backup/borg::first ~


# also possible: using sshfs or other locally mounted
# network filesystems, but be careful: worse performance

Links

borgbackup.github.io

#borgbackup on chat.freenode.net

Questions / Feedback?

• Just grab me at the conference!

• Thomas J Waldmann @ twitter