3 HDDs, all created around 2022-08-23 GMT. Default mountpoint folder: ipfs://QmSy7SZSx1jdrW8c8SayF7m1vVPHuqsC34WsswBH2s6R19 (via "ipfs add -rHw /media/ubuntu/easystore")

Info - "sudo smartctl -a /dev/sdx" =
Reallocated_Sector_Ct: 0
Current_Pending_Sector: 0
Power_On_Hours: 0
( Start_Stop_Count: 4 [an other one was 3]
Power_Cycle_Count: 3
Load_Cycle_Count: 6 [an other one was 7, an other one was 5]
Temperature_Celsius: 26 )

Long test - "TZ=UTC sudo smartctl -t long /dev/sdx". Test results - "sudo smartctl -a /dev/sdx | tail" should be "Completed without error". unmount, delete NTFS partition with "sudo fdisk /dev/sdx", ..., make zpool "sudo zpool create z3 /dev/sdx". Change ownership to normal user: "sudo chown ubuntu /z3". Export to set up next HDD: "sudo zpool export z3". Thanks https://linuxconfig.org/how-to-check-an-hard-drive-health-from-the-command-line-using-smartctl

It might be better to not delete NTFS partition and let ZFS use free space after deleting default files.