id = 1786
title = "Impossible to create an uncompressed QCOW2 disk"
state = "closed"
created_at = "2023-07-24T19:46:26.195Z"
closed_at = "2023-07-25T10:07:03.807Z"
labels = ["Storage", "qemu-img"]
url = "https://gitlab.com/qemu-project/qemu/-/issues/1786"
host-os = "Linux"
host-arch = "x86_64"
qemu-version = "n/a"
guest-os = "n/a"
guest-arch = "n/a"
description = """An QCOW2 image is created compressed unconditionally. There is no way to disable compression, albeit the QCOW format specification allows this.

```
$ qemu-img --version
qemu-img version 6.2.0 (Debian 1:6.2+dfsg-2ubuntu6.12)
Copyright (c) 2003-2021 Fabrice Bellard and the QEMU Project developers
$ qemu-img create -f qcow2 test.qcow2 1G
Formatting 'test.qcow2', fmt=qcow2 cluster_size=65536 extended_l2=off compression_type=zlib size=1073741824 lazy_refcounts=off refcount_bits=16
$
```

Same is applicable for 8-x qemu-img version (I built it for testing purposes)
```
$ ./build/qemu-img create -f qcow2 disk.qcow2 1G
Formatting 'disk.qcow2', fmt=qcow2 cluster_size=65536 extended_l2=off compression_type=zlib size=1073741824 lazy_refcounts=off refcount_bits=16
$ ./build/qemu-img --version
qemu-img version 8.0.90 (v8.1.0-rc0-21-gd1181d2937)
Copyright (c) 2003-2023 Fabrice Bellard and the QEMU Project developers
$ 
```"""
reproduce = """Create a QCOW2 disk with `qemu-img` of never versions."""
additional = "n/a"