My New Backup Setup with Kopia

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I’ve recently switched to Kopia after having some trouble with Duplicati. There was some sort of issue with mono (the runtime used by Duplicati) not reading the certificate files on my system, and failing to authenticate the Backblaze B2 connections. After most workarounds I read online not solving the issue, and the problem not being solved after months of waiting, I decided it might be time to check out some other backup solutions.

What I want from backup software

There are some features that I think are crucial for backup software.

  • Incremental backups. These save massive amounts of space, and it’s non-negotiable in my opinion. I’m not going to waste space storing a hundred duplicates of each file, any sane backup solution must be able to deduplicate the data in the backups.
  • Client-side encryption. While I have some level of trust for the services I’m backing up my data on, I don’t trust them to not read through my data. Between Google implementing a copyrighted material scanner and the said scanner going haywire, while I have nothing illegal in my backups I’d rather keep my data out of these services hands.
  • Compression is also important to me. A lot of the data on my computer that I want to back up is stuff like code files, configuration files, game saves and such. A lot of these files are not compressed well or at all, so compressing the backed up data can be a major win in terms of space savings. Modern processors can decompress data faster than disks can read or write them with the right algorithms, so this usually comes at effectively no cost too. Of course this may be less important for you if what you are trying to back up is already compressed data like images, videos, and music files.
  • Being able to restore only some files or folders without doing a full restore. Some services like Backblaze B2 charge you for data downloaded, so it’s important that if I’m only restoring a few files, I can do so without downloading the entire archive.


Kopia checks all these boxes. Backups are incremental, everything is encrypted client side. Compression is supported and is configurable, and you can mount your backups to restore only a subset of files or read them without restoring.

Something small that is amazing though is that Kopia can read .gitignore files to filter those files out of your backups! This is amazing as a developer because I already have gitignore files set up to ignore things like node_modules or project build directories, which I wouldn’t care about backing up. Thanks to Kopia, these are immediately filtered out of my backups without any extra effort.

Are incremental backups and compression really worth it?

Yes, absolutely!

Right now I have Kopia set up to back up my home directory, which contains about 9.8GB of data after all excluding all the cache files, video games, and applying gitignores. I have 13 snapshots of this, which in total take up 4.9GB on disk. 13 snapshots take less space than the entirety of my home directory!

I have Kopia set up to use pgzip compression which seems to be the best option in terms of compression speed versus storage size.