On Sat, 19 Mar 2022 at 19:01, Samuel Sieb samuel@sieb.net wrote:
On 3/19/22 14:48, George N. White III wrote:
On Sat, 19 Mar 2022 at 16:14, Samuel Sieb <samuel@sieb.net mailto:samuel@sieb.net> wrote:
On 3/19/22 05:18, George N. White III wrote: > Or just letting btrfs create over-sized "virtual partitions" and then > allocating > physical space as needed. btrfs doesn't do that. That's LVM thin-provisioning.
Fresh install of Fedora 35 using default installation in the free space (after shrinking the OEM Windows partition, leaving a little over 400
GB):
% df -lhT | grep btrfs /dev/nvme0n1p6 btrfs 405G 89G 316G 22% / /dev/nvme0n1p6 btrfs 405G 89G 316G 22% /home % sudo pvs -a PV VG Fmt Attr PSize PFree /dev/nvme0n1p1 --- 0 0 /dev/nvme0n1p2 --- 0 0 /dev/nvme0n1p3 --- 0 0 /dev/nvme0n1p4 --- 0 0 /dev/nvme0n1p5 --- 0 0 /dev/nvme0n1p6 --- 0 0 /dev/sda1 --- 0 0 /dev/sda2 --- 0 0 /dev/sdb1 --- 0 0 /dev/sdb2 --- 0 0
So the 405G btrfs shows / and /home sharing the 405G, and no PV's for lvm to use.
I don't know what you're trying to show there. "over-size virtual partitions" is LVM thin-provisioning. btrfs in your case has used the 405G partition and that's all the space that's available. It can be used by any of the btrfs volumes, but any space that's used by one volume is no longer available for the other ones. Every btrfs volume shows the same size.
If you meant something else by your initial comment, you'll need to explain it.
We are comparing the Fedora 35 default to manual partitioning. In btrfs terminology, /root is a top-level subvolume https://btrfs.readthedocs.io/en/latest/Subvolumes.html and /home is a . subvolume sharing storage with the top-level / filesystem. I just wanted point out that a default install doesn't need predetermined space requirements. Having said that, LVM helps adjust sizes based on in-use demands (but needs more steps to set up)..