[GLLUG] rdiff-backup presentation notes

[Charles Ulrich]

Since my train of thought seemed to have constantly off the rails all 
day yesterday, here are the notes for the rdiff-backup presentation 
that I had meant to hand out.

Charles



rdiff-backup
------------

http://rdiff-backup.stanford.edu/

Features:
- written in python
  - object oriented
  - very portable
  - author Ben Escoto responsive to bugs/feature requests
- mirroring
- incremental backups (snapshots)
- works over a network (via ssh) (from one remote to another remote)
- preserves:
  - subdirectories
  - hard links
  - device files
  - permissions
  - uid/gid ownership
  - modification times
- bandwidth efficient - only transmits the differences - uses librsync

Other backup systems
====================

cp
--

man cp

Works at the file level

cp -r <src> <dest>

- Easy to use
- wildcards skip dotfiles by default
- does not preserve modification times
- does not handle symlinks intelligently


dd
--

man dd

Works at the device level

dd if=<device> of=<out_file> bs=n count=n

- makes exact copies of entire device
- good for cloning disks of the same size (though not well suited for 
backup)

dump & restore
--------------

man dump
man restore

Work at the filesystem level (must have filesystem support)

# Mirror
(dump -0f - <src_mount> ) | (cd <dest> ;restore -rf -)

# Dump to file
dump -0f <dest> <src_mount>

# Restore interactively
restore -if <dest.out>

- The classic unix backup utilities
- Designed for tape, but can be used with any medium
- CANNOT backup arbitrary directories, only entire filesystems
- selective restore (only restore files you need) (interactive)
- incremental backups

Mondo Rescue
------------

http://www.microwerks.net/~hugo/

Creates complete bootable system restore discs

- Good for replicating OS installs

-- 
http://bityard.net