Edit the qcow2 FreeBSD image file

Johan Hendriks joh.hendriks at gmail.com
Wed Oct 4 10:01:39 UTC 2017

Op 04/10/2017 om 11:29 schreef Polytropon:
> On Wed, 4 Oct 2017 09:47:47 +0200, Johan Hendriks wrote:
>> I want to add a script to the default qcow2 file of the FreeBSD qcow2 image.
>> But how do i mount the qcow2 file on FreeBSD?
>> There are a lot of howto's how to do it on Linux but i do not always
>> have a Linux box ready.
> Without having verified, I'd say something like this will work:
> 	# mdconfig -a -t vnode -f <flename> -u 0
> 	# mount -t ufs -o rw /dev/md0s1a /mnt
> The key is to connect the file to a md device ("memory disk"),
> and then use it as if it was a real disk. But always check the
> correct device file name - md0 will reflect the "disk layout"
> of the image file, so maybe you need to use /dev/md0p1 or
> /dev/md0a or simply /dev/md0, so check "ls /dev/md0*" to see
> how the layout is being translated to device files - this
> depends on the layout that has been constructed within the
> image file.
> When you're done, use:
> 	# umount /mnt
> 	# mdconfig -d -u 0
> This will finally sync any changes and disconnect the device.
> The image file can be used now.
Thanks, I tried that, but it does not work.
root at desk:~ # mdconfig -a -t vnode -f FreeBSD-11.1-RELEASE-amd64.qcow2 -u 0

Then a ls of /dev/md0 only shows md0 and i can not mount that one.
root at desk:~ # ls -al /dev/md*
crw-r-----  1 root  operator  0x8c Oct  4 11:48 /dev/md0
crw-------  1 root  wheel      0xb Sep 21 14:16 /dev/mdctl

And a mount of /dev/md0 gives an error.

root at desk:~ # mount -t ufs -o rw /dev/md0 /mnt
mount: /dev/md0: Invalid argument


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