Toot from the #MachineRoom: Backups are made by stopping all Mastodon processes and the databases, syncing the file systems (remember "nodatacow") and then taking a #BTRFS snapshot. Then everything is started again. The snapshot is later pulled by the backup server. This all takes place between 2:10 and 2:20 UTC and take around 30s. This will not increase very much for a few thousand active users.