bttrfs deprecated by redhat, development has slowed.

works on bare metal and virtual machines.

traditional, block devices for raid, lvm, encryption, etc.

zfs: COW

pools of virtual devices.

VDEV = virtual devices.

ZFS Pools

Datasets

ZVOLS - ZFS volumes

• block devices
• swap devices

SLOG/ZIL - ZFS Intent Log

Not all disks need to be the same size.