For a single-drive pool, both ZFS and ext4 are viable options, but they serve different purposes:
ZFS advantages on a single disk:
- Data integrity: Detects corruption through checksumming (though it can't auto-repair without redundancy)[1][8]
- Snapshots and compression: Built-in features that ext4 lacks[1][4]
- Future flexibility: Easy to convert to a mirrored pool later by adding another drive[1]
- Self-healing with copies=2: You can set ZFS to store multiple copies of data on the same disk, enabling some corruption recovery[1]
ext4 advantages:
- Lower overhead: Less resource-intensive (RAM, CPU) than ZFS[3][4]
- Better performance: Generally faster on single disks, especially for random writes[4]
- Simpler: Fewer configuration options and less complexity[7]
Recommendation: If data integrity and snapshots matter to you, choose ZFS—it will alert you to corruption even on a single disk[5][7]. If performance and simplicity are priorities, stick with ext4[3][4]. For backup storage specifically, ZFS is often preferred despite the overhead because detecting corruption is critical[7].