What is a good, secure, method to do backups, for programmers who do research & development at home and cannot afford to lose any work?
Conditions:
The backups must ALWAYS be within reasonably easy reach.
Internet connection cannot be guaranteed to be always available.
The solution must be either FREE or priced within reason, and subject to 2 above.
Status Report
This is for now only considering free options.
The following open-source projects are suggested in the answers (here & elsewhere):
BackupPC is a high-performance,
enterprise-grade system for backing
up Linux, WinXX and MacOSX PCs and
laptops to a server's disk.
Storebackup is a backup utility
that stores files on other disks.
mybackware: These scripts were
developed to create SQL dump files
for basic disaster recovery of small
MySQL installations.
Bacula is [...] to manage
backup, recovery, and verification
of computer data across a network of
computers of different kinds. In
technical terms, it is a network
based backup program.
AutoDL 2 and Sec-Bk: AutoDL 2
is a scalable transport independant
automated file transfer system. It
is suitable for uploading files from
a staging server to every server on
a production server farm [...]
Sec-Bk is a set of simple utilities
to securely back up files to a
remote location, even a public
storage location.
rsnapshot is a filesystem
snapshot utility for making backups
of local and remote systems.
rbme: Using rsync for backups
[...] you get perpetual incremental
backups that appear as full backups
(for each day) and thus allow easy
restore or further copying to tape
etc.
Duplicity backs directories by
producing encrypted tar-format
volumes and uploading them to a
remote or local file server. [...]
uses librsync, [for] incremental
archives
Other Possibilities:
Using a Distributed Version Control System (DVCS) such as Git(/Easy Git), Bazaar, Mercurial answers the need to have the backup available locally.
Use free online storage space as a remote backup, e.g.: compress your work/backup directory and mail it to your gmail account.
Strategies
See crazyscot's answer