What I Would Do If I Ran Tarsnap

Interesting article. I'd actually not heard of Tarsnap before, one question (to those who use it), why would a geek use it over:

  tar -cf - / --exclude='/proc/*' --exclude='/dev/*' [..] | \
      xz -z | \
      openssl enc -aes-256-cbc -e -salt | \
      > /mnt/your/networked/google/drive/backup.$(hostname -a).$(date "+%Y%m%d-%H%M%S").aes.tar.xz

I spent a while going through https://www.tarsnap.com/ and I didn't find any flexibility tarsnap offers over it. To make it work unattended, it's trivial to generate a unique key per backup for openssl (use a tmpfs) and then gpg encrypt the key and email it to sys admins or whatever mailing list before killing the tmpfs.

I could understand the appeal to less tech savvy users if there were a gui, or it featured cross platform support beyond those supported by tar, <insert compression tool>, openssl/aespipe/gpg/<insert encryption tool>, or the storage was super cheap.

So what's the value proposition here?

Data deduplication, incremental backups.

HEAD-DESK.

Deduplication and incremental backups are table-stakes for backup software.

The reason a business would use Tarsnap rather than some other backup service is the level of confidence that Colin can provide that Tarsnap will reliably protect their data from attackers, including compelled insiders at Tarsnap.

In other words, Tarsnap can offer an enterprise an offsite backup service that is demonstrably as safe as backup data that the enterprise retains direct custody of.

That is not an offering other backup providers can reliably duplicate.