Re: [Qemu-block] [Libguestfs] [Qemu-devel] [qemu-img] support for XVA

[Max Reitz]

On 2017-11-16 11:08, Gandalf Corvotempesta wrote:
> 2017-11-15 23:55 GMT+01:00 Max Reitz <address@hidden>:
>> https://xanclic.moe/convert-xva.rb -- does this work?
>> (It seems to works on the two example images I found...)
>>
>> An example is in the code, you use it like this:
>>
>> $ ./convert-xva.rb ~/Downloads/stats-appliance-2.36.020502.xva Ref:73
> 
> 
> It doesn't work on huge images:
> 
> # time convert-xva.rb 20171115_193814_efff_.xva Ref:10 -O qcow2 disk1.qcow2
> /usr/bin/convert-xva.rb:119:in `exec': Argument list too long -
> qemu-img (Errno::E2BIG)
> from /usr/bin/convert-xva.rb:119:in `<main>'
> 
> real 9m41.414s
> user 0m19.280s
> sys 0m3.260s

Well, there is this:

https://github.com/XanClic/qemu.rb/blob/master/examples/convert-xva-online.rb

That should get around that restriction, but currently it is stupidly
slow (because it just issues all 1 MB copy operations simultaneously),
and it doesn't use qemu-img convert.  Instead, it uses a real qemu with
block jobs.  Ideally, you'd use it like this:

$ ./convert-xva-online.rb ~/Downloads/stats-appliance-2.36.020502.xva
Ref:73      81936 M
$ qemu-img create -f qcow2 [whatever options you need] disk1.qcow2 \
    81936M
Formatting 'disk1.qcow2', fmt=qcow2 size=85916123136 encryption=off
cluster_size=65536 lazy_refcounts=off refcount_bits=16
$ ./convert-xva-online.rb ~/Downloads/stats-appliance-2.36.020502.xva \
    Ref:73 \
    '{"driver":"qcow2",
      "detect-zeroes":"unmap",
      "discard":"unmap",
      "file":{"driver":"file","filename":"disk1.qcow2"}}'
Adding block devices...
Starting block jobs...
100.00 % of jobs completed

(Maybe I can get it faster.)

Max

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