Basically everything related to multiple disks is super basic and too simple.
1. If you are writing with the `single` profile. It always writes to the one with the most space. This means that adding a new disk to a system will hotspot writes to that disk. Alternatively you can rebalance and it will make it so that all disks have the same space available which will basically hotspot reads. Most sane filesystems will do some sort of balancing.
2. If you are writing to the `RAID0` (striping with no redundancy) it will write across all disks and fill them up equally. When one disk fills it will be dropped out and the other disks will be hotspotted.
3. If you read from a replicated profile it picks the disk based on your process ID rather than any sort of intelligent metric like queue length or typical latency.
4. Replication profile can only be set on the filesystem level. bcachefs can set replication profile on the per-file or recursively at the directory level.
I mean nothing is absolutely terrible. But it is just shockingly basic for many things.
1. If you are writing with the `single` profile. It always writes to the one with the most space. This means that adding a new disk to a system will hotspot writes to that disk. Alternatively you can rebalance and it will make it so that all disks have the same space available which will basically hotspot reads. Most sane filesystems will do some sort of balancing.
2. If you are writing to the `RAID0` (striping with no redundancy) it will write across all disks and fill them up equally. When one disk fills it will be dropped out and the other disks will be hotspotted.
3. If you read from a replicated profile it picks the disk based on your process ID rather than any sort of intelligent metric like queue length or typical latency.
4. Replication profile can only be set on the filesystem level. bcachefs can set replication profile on the per-file or recursively at the directory level.
I mean nothing is absolutely terrible. But it is just shockingly basic for many things.