> BRTFS-raid2 seems to be good for up to 8 drives if that is your use case. But there is no easy upgrade path to that 9th drive. You should not be running less

> BRTFS-raid2 seems to be good for up to 8 drives if that is your use case. But there is no easy upgrade path to that 9th drive. You should not be running less than 3 drives for any data you care about. What the hell? Can you please clarify what you mean by "BRTFS-raid2", since that's not a term that has previously existed and BTRFS does not have any functionality remotely similar to the long-obsolete traditional RAID2, and none of the RAID functionality that BTRFS does have has any limitations or safety thresholds for going beyond 8 drives, especially not the RAID1 mode (which is the most plausible thing your raid2 could have been a typo of). If you have an 8-drive btrfs RAID array, going to 9 drives is as simple as `btrfs device add`, optionally followed by a `btrfs balance start`. Neither of those will reduce the redundancy of any data stored in the array. And I can't see any reason why you're suddenly talking about 3 drives right after talking about 8 or 9 drives.