On 3/17/21 10:37 PM, qi zhou wrote:
When I create vhdx differencing disk using qemu-img, It says
qemu-img: xxx.vhd Backing file not supported for file format 'vhdx'
The command I used is
qemu-img create -f vhdx -b test.vhdx test-snapshot.vhdx
Here is my questions
1. Is vhdx format [full] supported by qemu ?
We support raw and qcow2 fully, read-write.
Everything else is "read-only", though write support might work, we
don't encourage its use in production environments.
2. If not, is there any easy way to implement differencing disk of vhdx in
qemu-img ?
the -b flag is generally for qcow2 files; I am not very familiar with
VHDX but it appears as though we don't support it here.
I imagine it's
https://www.altaro.com/hyper-v/hyper-v-differencing-disks-explained/ ?
I don't think we support those... ah, yeah, in block/vhdx.c:
typedef enum VHDXImageType {
VHDX_TYPE_DYNAMIC = 0,
VHDX_TYPE_FIXED,
VHDX_TYPE_DIFFERENCING, /* Currently unsupported */
} VHDXImageType;
3. Is there any other tools support vhdx on linux ?
Not that I'm aware of, but I can't say I've looked before.
