How to do it...

To obtain Debian Wheezy images for use with QEMU and KVM, perform the following:

1. Download the image using wget: 

root@kvm:~tmp# wget https://people.debian.org/~aurel32/qemu/amd64/debian_wheezy_amd64_standard.qcow2    
--2017-03-09 22:07:20-- 2    Resolving people.debian.org (people.debian.org)... 2001:41c8:1000:21::21:30, 5.153.231.30    Connecting to people.debian.org (people.debian.org)|2001:41c8:1000:21::21:30|:443... connected.    HTTP request sent, awaiting response... 200 OK    Length: 267064832 (255M)    Saving to: ‘debian_wheezy_amd64_standard.qcow2’    debian_wheezy_amd64_standard.qcow2 100% .  [===================================>] 254.69M 35.8MB/s in 8.3s    2017-03-09 22:07:29 (30.9 MB/s) - ‘debian_wheezy_amd64_standard.qcow2’ saved [267064832/267064832]    
root@kvm:~#

1. Inspect the type of the image:

root@kvm:~# qemu-img info debian_wheezy_amd64_standard.qcow2    
image: debian_wheezy_amd64_standard.qcow2    
file format: qcow2    
virtual size: 25G (26843545600 bytes)    
disk size: 261M    
cluster_size: 65536    
Format specific information:    
compat: 1.1    
lazy refcounts: false    
refcount bits: 16    
corrupt: false    
root@kvm:~#

To download CentOS images run the following commands:

1. Download the image using wget:

root@kvm:/tmp# wget         https://cloud.centos.org/centos/7/images/CentOS-7-x86_64-GenericCloud.qcow2    --2017-03-09 22:11:34-- https://cloud.centos.org/centos/7/images/CentOS-7-x86_64-GenericCloud.qcow2    Resolving cloud.centos.org (cloud.centos.org)... 2604:4500::2a8a, 136.243.75.209    Connecting to cloud.centos.org (cloud.centos.org)|2604:4500::2a8a|:443... connected.    HTTP request sent, awaiting response... 200 OK    Length: 1361182720 (1.3G)    Saving to: ‘CentOS-7-x86_64-GenericCloud.qcow2’
CentOS-7-x86_64-GenericCloud.qcow2 100%[=========================================>] 1.27G 22.3MB/s in 54s
2017-03-09 22:12:29 (24.0 MB/s) - ‘CentOS-7-x86_64-GenericCloud.qcow2’ saved [1361182720/1361182720]
FINISHED --2017-03-09 22:12:29--    Total wall clock time: 54s    Downloaded: 1 files, 1.3G in 54s (24.0 MB/s)    
root@kvm:/tmp#

1. Inspect the type of the image:

root@kvm:~# qemu-img info CentOS-7-x86_64-GenericCloud.qcow2    
image: CentOS-7-x86_64-GenericCloud.qcow2    
file format: qcow2    
virtual size: 8.0G (8589934592 bytes)    
disk size: 1.3G    
cluster_size: 65536    
Format specific information:    
compat: 0.10    
refcount bits: 16    
root@kvm:~#