FreeBSD 13.0 terrible performance in KVM

[Crest]

On 25.04.21 11:15, dashdruid via freebsd-stable wrote:

> Hello,
>
> I have reinstalled it with GPT/ZFS and your right it's much better. Same search taking 3-6 seconds so I have deleted now all my old UFS based FreeBSD images.

If the partitioning alone changed something it was probably an alignment 
problem. These are things you can try:

* Create a VM with two virtual disks.

* Install a UFS system on the first disk.

* Create and mount a UFS on the unpartitioned second disk.

* Copy the whole system with tar to the second disk.

* Reboot the VM.

* Compare performance on both file disks.

Maybe your virtual disk backend is is just terrible with unaligned accesses.