We are migrating a working server from LVM to ZFS (pve 8.2).
The system currently has 3 NVMe 1Tb disk, and we have added a new 2Tb one.
As we haven't found a clear/easy way to migrate the running system, and on the other hand, we are stuck with an issue with kernel updates too, we thought about performing a clean ISO install to the new disk to then migrate manually the root system config (still looking for a guide for that), create a thin ZFS to migrate the containers and once our "old" 3 NVMe disks are free of data, add them to the original reinstalled ZFS main pool. In order to achieve this, we understand we would need to limit the new ZFS rpool to the size of the 1Tb disks, so they can be added with exactly the same size as the main one after.
When getting to install the new system, I've discovered that the installation options to limit the size of root partition (maxroot) does not apply when choosing ZFS so have various doubts of the process:
Our only alternative otherwise as I see it would be shrinking our current PVE vgroup to only hold root (already messy) and then using the rest of each disk for the ZFS rpool only for containers, but that would leave us with LVM+RAID+ZFS on the system which I would rather avoid too and likely would rather have a clean install too.
The system currently has 3 NVMe 1Tb disk, and we have added a new 2Tb one.
As we haven't found a clear/easy way to migrate the running system, and on the other hand, we are stuck with an issue with kernel updates too, we thought about performing a clean ISO install to the new disk to then migrate manually the root system config (still looking for a guide for that), create a thin ZFS to migrate the containers and once our "old" 3 NVMe disks are free of data, add them to the original reinstalled ZFS main pool. In order to achieve this, we understand we would need to limit the new ZFS rpool to the size of the 1Tb disks, so they can be added with exactly the same size as the main one after.
When getting to install the new system, I've discovered that the installation options to limit the size of root partition (maxroot) does not apply when choosing ZFS so have various doubts of the process:
- any way to limit the size of root which I am guessing it will be hdsize/4?
- alternatively, will I be able to easily resize (reduce) root after install via ZFS commands?
- alternatively, will I be able to easily resize (reduce) root after install via ZFS commands?
- which ZFS raid format should I select on the installer if only installing to one disk initially? Considering that
- I can assume loosing half of the space in favour of more redundancy in a RAID10 style.
- I understand my final best config should end up in 2 mirrored vdevs of approx 950Gb each (Raid 10 style), so I will have to use "hdsize" to limit. Still have to find out how to determine exact size.
- Or should I consider RAIDZ2? In which case... will the installer allow me to? I am assuming it will force me to select the 4 disks from the beginning.
Our only alternative otherwise as I see it would be shrinking our current PVE vgroup to only hold root (already messy) and then using the rest of each disk for the ZFS rpool only for containers, but that would leave us with LVM+RAID+ZFS on the system which I would rather avoid too and likely would rather have a clean install too.