Re: [Qemu-devel] Question about vNVDIMM file format

[Xiao Guangrong]

On 05/16/2016 11:04 PM, Richard W.M. Jones wrote:
> I'm playing with ext4 and DAX.

Thanks for your try, Rich! :)

> I'm using:
>
>    -object memory-backend-file,id=mem1,share,mem-path=/var/tmp/pmem,size=4G \
>    -device nvdimm,memdev=mem1,id=nv1
>
> where /var/tmp/pmem is a 4 GB ext4 filesystem image (no partition
> table).  I can mount this in the guest using:
>
>    mount -o dax /dev/pmem0 /mnt
>
> and everything appears to work.
>
> I read in the mailing list that the pmem file has some internal
> structure for storing config data, stored in the last 128 KB of the
> file.  Is that still the case?

The patchset supporting label data has not been merged yet so currently there
is no label data for vNVDIMM device.