[Qemu-devel] "qemu-img: File contains external, encrypted or compressed clusters."

[Richard W.M. Jones]

This error message is confusing and looks wrong to me:

$ ./nbdkit -U - data data="1" size=1M --run 'qemu-img map $nbd'
Offset          Length          Mapped to       File
qemu-img: File contains external, encrypted or compressed clusters.

With JSON output it's fine:

$ ./nbdkit -U - data data="1" size=1M --run 'qemu-img map --output=json $nbd'
[{ "start": 0, "length": 32768, "depth": 0, "zero": false, "data": true},
{ "start": 32768, "length": 1015808, "depth": 0, "zero": true, "data": false}]

Looking at the source code the error seems to be related to the first
extent having data=true but no "offset" (whatever that is), but I
don't understand what it's trying to say.

It doesn't happen with local sparse files:

$ virt-builder fedora-28
$ qemu-img map fedora-28.img 
Offset          Length          Mapped to       File
0               0x10000         0               fedora-28.img
0x100000        0x10000         0x100000        fedora-28.img
0x200000        0xb0000         0x200000        fedora-28.img
[etc]

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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