User Savagedlight shows us how to replace a drive on a FreeBSD system using only one drive and ZFS, without disrupting its availability. Check out the video below for the full walk-through.
Recap of the video
- Prequisite: A standard FreeBSD 12.0 install with root on ZFS, where the root pool is smaller than the amount of system memory. (in my case: 8GB system memory, 4GB root pool)
- Replace existing drive with a memory-backed block device
- Physically remove the existing drive
- Verify the system still works
- Physically attach new drive to system
- Replace memory-backed block device with new drive
- Bonus: Reboot system, verify it boots from new drive.