It's been a while since I have written about my backup strategy, so I figured I would give it an update.
For those of you who don't know, I use Ubuntu across all of my computers. Starting a few years ago, I began using Dropbox Plus mainly for their version history. Whenever I do a clean install of Ubuntu, I delete all of the stock folders such as Documents, Downloads, Pictures, etc. and replacing them with symbolic links to folders inside of Dropbox. This not only keeps my home directory in sync across all of my computers, it now, by upgrading to the professional Dropbox plan, automatically gives me a 180 version history for all of my files.
Step two is me having multiple cron jobs running every twelve hours that copies the entirety of my Dropbox directory to Google Drive as well as an Amazon S3 bucket in the Northern Virginia region. On the primary S3 bucket, I have a replication rule that replicates every file to another bucket in the Tokyo region using the Deep Glacier class to save on storage costs.
On my more sensitive directories such as Documents, source code, etc., I have cron jobs running every five minutes to copy each of the directories to Google Drive, S3, Microsoft OneDrive, Box.net , and pCloud.
Thirdly, at the beginning of every month, I take out an external hard drive out of my fireproof safe and do a full copy of my Dropbox directory.
Lastly, since the S3 Deep Glacier storage class is so cheap ($1/per terabyte/per month), I compress my entire Dropbox directory every six months and store it, rotating them out every two years.
I know this is just a tad bit overkill, but I sleep very well at night knowing my data is safe!