KVM/QEMU thin provision sanal disk oluşturma

Eğlencelik ● 16/11/2015

Thin Provision KVM / QEMU Virtual Disk

If you want to create a Thin Provisioned disk and actually want to use it ;-) You need to add:
-o preallocation=metadata

My following example I would like to create 2 disks for my Satellite (lab) host. (I would not thin provision my production Satellite server - for a number of reasons). I am building a test Satellite on my laptop which introduces some additional caveats.
notice that 199M is consumed, but when you view the files, they appear to be 120Gig total.

SATHOSTNAME=RHNSAT01

OSDISKSIZE=18

APPDISKSIZE=100

qemu-img create -f qcow2 -o preallocation=metadata /var/lib/libvirt/images/${SATHOSTNAME}/${SATHOSTNAME}.img ${OSDISKSIZE}G
[root@neo ~]# df -h /var/lib/libvirt/images/RHNSAT01
[root@neo ~]# ls -lh
[root@neo RHNSAT01]# qemu-img info RHNSAT01-app.img
[root@neo RHNSAT01]# qemu-img info RHNSAT01-app.img
[root@neo RHNSAT01]# qemu-img info RHNSAT01.img

qemu-img create -f qcow2 -o preallocation=metadata /var/lib/libvirt/images/${SATHOSTNAME}/${SATHOSTNAME}-app.img ${APPDISKSIZE}G

Filesystem Size Used Avail Use% Mounted on

/dev/mapper/vg_neo-VM_RHNSAT01

60G 199M 56G 1% /var/lib/libvirt/images/RHNSAT01

total 19M

drwx------. 2 root root 16K Jun 25 11:33 lost+found

-rw-r--r--. 1 root root 101G Jun 25 13:13 RHNSAT01-app.img

-rw-r--r--. 1 root root 19G Jun 25 13:13 RHNSAT01.img

image: RHNSAT01-app.img

file format: qcow2

virtual size: 100G (107374182400 bytes)

disk size: 16M

cluster_size: 65536

image: RHNSAT01.img

file format: qcow2

virtual size: 18G (19327352832 bytes)

disk size: 3.0M
cluster_size: 65536