Anyone planning on ZFS or BTRFS for file systems?

[Arwen]

It's difficult to argue the use cases for either file system with the characteristics of the PineBook Pro laptop.

These file systems are meant for scenarios where there is redundancy in the form of multiple drives.

Trying to apply ZFS or Btrfs to eMMC alone may be worse than not using either system - it could be all working fine one moment but corruption in the wrong place means total loss of everything and no way to fix it at all - in similar situations, other file systems could recover.

Adding a single NVMe to the mix improves matters a little but only a little and it's still far from ideal. Obviously, you could hold two copies for a pool on the NVMe drive, for half the effective storage capacity with every block stored twice in the pool. But when the drive fails everything will be lost.

Much better to implement these file systems on a separate computer with multiple drives and take regular backups from the PineBook Pro to this computer. And run a lightweight file system on the PineBook Pro that can recover from errors. This is a much safer scenario.

A couple of things about ZFS. All metadata, (directory entries, etc...), have a minimum of 2 copies, even without any Mirroring. With Mirroring, I'd end up with 2 copies PER sub-mirror, 4 total. Critical metadata has even more copies. So file system corruption is less likely with ZFS than most file systems.

I've actually booted a MicroSDXC card with ZFS on Linux. Quite usable. Yes, slow, but it was only for on-line backup and recovery media.

Already have a NAS with ZFS for backups and general, long term storage.

The reasons to use ZFS out-weigh the negatives. I WANT to detect file system corruption. Been bit a few times in the past where either bad disk blocks or damaged file system blocks caused un-known corruption. Then I had trouble recovering. With ZFS I'd at least know about it, even if I could not recover that pool.

Yes, Mirroring across eMMC & NVME may seem a bit silly. But, at present 2 of my Linux computers mirror SSD to a piece of HD. It works. Bad blocks or complete failure of either device is not catastrophic. My current laptop, (now slow due to Intel's new Meltdown & friends upgrade), uses a single 1TB SATA SSD with 2 partitions mirrored for the OS.

Natually this would be an experiment. If I find ZFS or BTRFS un-reliable, (either because it's ARM64, or slower CPU), I can go back to EXT4 or XFS. If I travel before I consider the experiment done, then I'd likely take my old laptop along as a backup device.