Some thoughts on NextCloud

8th September 2021

OK so you what if want the convenience of easy file synchronisation and sharing that only a cloud service can provide, but you don't want to give all your data to one of the tech deities.

In this case you may decide to set up a Nextcloud instance.

Now when I first considered using NextCloud the main thing that worried me was the same thing that worries me about self-hosting anything. That maintaining a web-service properly requires:

• updates
• security
• monitoring
• backups

...which I can't reasonably commit all that effort for a service that only one person is using. Also if something breaks I might not get time to fix it until the weekend.

But an important epiphany I had is that as Nextcloud is just a synchronisation tool, so if you're just using it for yourself you can actually not bother backing-up the server at-all and just backup your files client-side instead.

Let me present an example. Assume you have at-least one device which is synchronising all off the files in your Nextcloud. And your Nextcloud is running on a Raspberry Pi in your house. Now imagine someone flushes that Raspberry Pi down the toilet and you have no backups of it.

Actually you haven't lost any data because all of your files are just on the disk of one (or more) of your computers. You just temporarily don't have synchronisation and file-sharing functionality until you set up a new NextCloud.

So you can just handle all your backups client-side (backup to a USB HDD or something) and treat Nextcloud as nothing more than a disposable cache of your data.

But what if you are also using Nextcloud for calendar and contacts? Well you can easily export them as interoperable formats (ICS and VCF). So if you just do that before making your backups to a USB HDD or whatever then you're all good.

Not let's imagine a few different scenarios and what the outcome would be.

• You are working on your laptop in a hotel with an internet connection. Later in the day you lose it on the train and never get it back.
  No data loss as it would have synchronised up-to Nextcloud already (however if you are not using disk encryption a thief can read all your files).
• Unexpected destruction of server.
  No data loss and still have access to backups.
• Entire internet vanishes forever.
  No data loss and still have access to backups.
• Your Nextcloud is hosted on a rented virtual server. Someone breaks into your house and steals all your computers and your backup drive too.
  No data lost as it's all still in Nextcloud (but heed note about encryption in first example).
• Your Nextcloud is hosted on a Raspberry Pi in your house. Someone breaks into your house and steals all your computers and your backup drive and your Raspberry Pi.
  Complete, irrecoverable loss of all data (also heed note about encryption in first example).
• You are on holiday in a remote location with no internet and you didn't bring your backup drive. Your laptop is destroyed.
  Of-course Nextcloud is useless without internet so you lose all data since the last time you had an internet connection.
• Malicious entity gains control of your Nextcloud account and deletes all your files.
  The deletion is synchronised to all devices so you lose all files since your last backup.
• Malicious entity gains control of your Nextcloud account and studies the files to steal your data.
  If there are any sensitive files or anything that could be used for identity theft this could be a huge problem.

So basically as long as you have client-side backups data-loss isn't normally a big concern. However data theft is definitely a concern. Identity theft can ruin people's lives. Imagine if someone keeps opening credit cards in your name and you have no way to stop them. So you should:

• definitely use disk-encryption on all devices and backup drives.
• definitely if you are self-hosting a Nextcloud be sure to keep it up-to-date and that you know how to secure it
• consider applying file-level encryption such a PGP to any files that contain sensitive data. Or avoiding storing certain data on a cloud service.

Conclusion

I think cloud file services are really useful for a big variety of reasons:

• keep files in-sync between different computers
• easily share links to your files with other people
• easily access your files on library computer just by logging into a website
• complements your backups solution as (if you have an internet connection) it instantly copies all your files

Just take care about the security aspect as it's the most scary part about the whole cloud thing.