On btrfs causing latency: I've got a few systems with btrfs as the rootfs (on top of lvm, on top of dm-crypt, on a SSD). I recently started using `snapper` to

On btrfs causing latency: I've got a few systems with btrfs as the rootfs (on top of lvm, on top of dm-crypt, on a SSD). I recently started using `snapper` to create snapshots on a schedule on them. I enabled quota support in btrfs so I could see how much space snapshots were using. I noticed that filesystem wide latency tended to spike when removing snapshots (several minutes of all fs access stalling). Balancing with quotas enabled is even worse: my systems were hung for multiple days, until I forcibly restarted them and disabled quotas. Then the fs hangs were much smaller (a few seconds) and not to noticeable. Balancing finished in something on the order of an hour. While I had quotas enabled, I was constantly having btrfs tell me the data was bad and needed rescanning (rescanning quotas would also induce fs wide latency). The thing is, ZFS has snapshot space usage info, and doesn't have awful latency (it also doesn't have a "balance" operation, but I'm not sure how relevant that is). Given my experience with both btrfs & ZFS, I'll likely consider using ZFS as my rootfs in the future.