Please make sure you installed the errata for 6.4 (syspatch will do it for you, don't forget to reboot!). There was a bug that was fixed in errata 008: "writing more than 4GB to a qcow2 volume corrupts the virtual disk".
On 2019 Apr 18 (Thu) at 10:06:59 +0200 (+0200), Malte Wedel wrote: :Hello OpenBSD, : :I was trying to run Linux inside vmm, by converting an existing :vmdk-image to qcow2 using qemu-img. While the configuration and setup :seems to be straightforward, I had filesystem corruption issues on the :ext4-fs inside the VM. : :This happened on two separate occasions - in the first try I was booting :from the cd iso-image and mounted the disk to enable serial console. As :soon as I changed files on the mounted disk I got errors, unmounting and :running fsck could not repair. : :The next try I booted the VM on a different machine, enabled serial :console there, and then converted to qcow2. This time the machine did :boot up once, but failed due to filesystem errors as soon processes :started to write to the filesystem. I was not able to boot it again. : :When converting the same vmdk image to raw instead of qcow2 the VM did :start up and run without issues. : :I am running OpenBSD 6.4. Are there known issues with qcow2 in vmm? :Anything I can do to help understand/analyze the issue? : :Regards, :Malte : : -- All true wisdom is found on T-shirts.
