I have a website which works with lots and lots of text files - now they take up about 40 GB of data and increasing over time. I need to make a full daily backup. My current strategy is to make a password protected archive and store it in the dropbox with this command:
tar cfz - /var/www/mysite | openssl enc -aes-256-cbc -e -k "b@ckupPassword" > /home/user/Dropbox/server_backups/sources/2013_01_04_0500_mysite_source_encrypted.tgz
It works, but making an archive takes about 14 hours and consumes a lot of IO - and it will be worse as the amount of data increases.
What is the proper strategy of backing up such large amount of files?