How do you backup your NextCloud?

A Nextcloud backup is three things you cannot skip — the config folder, the data folder and the database — copied together while the server is in maintenance mode. No app does this for you on the current release: the app called Backup in Nextcloud's own store cannot be installed on Nextcloud 34.

Everything below was checked in September 2026 against a fresh Nextcloud 34.0.3 — the official Docker image, on a Linux server — and the version 34 administration manual. The manual's commands assume Nextcloud installed directly on Linux; if yours runs in Docker, the Docker versions are further down.

Is there a Nextcloud backup app?

There is one called Backup, and on the version you would install today it is not an option. Search the app store on Nextcloud 34 for "backup" and three apps come up — Backup, NextBackup and OwnBackup — with no install button on any of them. Backup's details read: "This app cannot be installed because the following dependencies are not fulfilled: Server version 28 or lower is required." It was last updated in January 2024. NextBackup requires version 20 or lower, OwnBackup 17 or lower.

That does not mean Backup was abandoned. It means there is no release of it for anything newer than Nextcloud 28.

An earlier version of this page described "External Storage Support" as a built-in backup app. It is not one. It mounts other storage inside Nextcloud; it does not copy your server anywhere.

What does a Nextcloud backup need?

The administration manual lists five things to retain:

1. The config folder
2. The custom apps folder (only if you have custom apps installed)
3. The data folder
4. The theme folder
5. The database

Three of them you cannot restore without. The data folder is your files. The config folder is how the server is set up. The database is what makes those files Nextcloud: accounts, shares, and the record of every file and where it lives. The restore page says it flatly: "You must have the database, data directory, and configuration files. You cannot complete restoration without all three."

Why turn on maintenance mode first?

In the manual's words, maintenance mode "locks the sessions of logged-in users and prevents new logins in order to prevent inconsistencies of your data."

If someone uploads while you are copying, the files and the database can end up from different moments. The backup looks complete and is not. The restore page describes what that looks like afterwards: when the database is newer than the data directory, "the files would be visible but not accessible."

How do you back up Nextcloud, step by step?

1. Turn on maintenance mode: sudo -E -u www-data php occ maintenance:mode --on
2. Copy the config, data and theme folders somewhere outside your Nextcloud server — or the whole installation directory, which the manual also allows: rsync -Aavx nextcloud/ nextcloud-dirbkp_`date +"%Y%m%d"`/
3. Dump the database. For MariaDB: mariadb-dump --single-transaction -h [server] -u [username] -p[password] [db_name] > nextcloud-sqlbkp_`date +"%Y%m%d"`.bak. For PostgreSQL: PGPASSWORD="password" pg_dump [db_name] -h [server] -U [username] -f nextcloud-sqlbkp_`date +"%Y%m%d"`.bak
4. Turn maintenance mode off again: sudo -E -u www-data php occ maintenance:mode --off
5. Restore it once, onto a test server, from the backup alone. A backup you have never restored is a guess.

Once that works by hand, put the same steps in a script and schedule it with cron. Keep at least one copy somewhere other than the server it came from.

How do you back up Nextcloud in Docker?

The same three things matter; they just live somewhere else. In the official Docker image, the config and data folders are inside the Nextcloud volume (/var/www/html), and the database runs in its own container with its own volume. Nextcloud's Docker documentation says a backup needs "one volume for your database container and one for Nextcloud". Replace the container and volume names with yours (docker ps and docker volume ls list them):

1. Maintenance mode on — occ runs inside the Nextcloud container: docker exec --user www-data nextcloud php occ maintenance:mode --on
2. Copy config, data, themes and custom apps out of the Nextcloud volume: docker run --rm -v nextcloud:/src:ro -v "$PWD":/backup alpine tar czf /backup/nextcloud-vol.tar.gz -C /src config data themes custom_apps
3. Dump the database from its container. PostgreSQL: docker exec nextcloud-db pg_dump -U nextcloud nextcloud > nextcloud-sqlbkp.bak. MariaDB: docker exec nextcloud-db mariadb-dump --single-transaction -u nextcloud -p[password] nextcloud > nextcloud-sqlbkp.bak
4. Maintenance mode off: docker exec --user www-data nextcloud php occ maintenance:mode --off

If you mounted host folders instead of named volumes, copy those folders directly, exactly as in the manual's steps above.

Can you run a Nextcloud server on Windows?

Not directly. The operating systems listed in Nextcloud's system requirements for the server are all Linux: Ubuntu, Red Hat Enterprise Linux, Debian and SUSE. Windows appears there only for the desktop sync app. Guides that "install Nextcloud on Windows" run it inside Docker Desktop, WSL or a virtual machine — which is Linux underneath — so the Docker steps above are the ones that apply.

What if you installed Nextcloud All-in-One?

Then you have a backup built in. The All-in-One project's own documentation: "Nextcloud AIO provides a backup solution based on BorgBackup." It is run from the AIO interface, including restore. Everyone else follows the manual above.