[CentOS] KVM Questions

[Paul R. Ganci]

On 05/08/2015 11:41 PM, James Hogarth wrote:
> was wondering if this procedure might work to do what I desire:
>
> 1.) Shutdown the VMs
> 2.) Archive the VM image directory /home/vmimages to a network drive
> 3.) Use parted or fdisk to delete present /home partition
> 4.) Use parted or fdisk to re-create smaller/home partition and new vm-images
> 5.) Create XFS file system on /home and /vm-images
> 6.) Extact VM image directory archive into /vm-images
> 7.) Use virt-manager to change default location of images to /vm-images
>
> Is there any chance that after all this the VMs would actually start up
> again especially after a re-boot?
>
>> They are just disk images so as long as you don't mind deleting home then
>> this will work.
So it turns out this was even easier than I expected. The home partition 
was actually built upon LVM so some relatively simple use of LVM allowed 
me to do exactly what I wanted. However I have some very subtle issue 
that I don't understand. virt-manager, df and du incorrectly think this:

> df
Filesystem                               1K-blocks     Used Available Use% Mounted on
/dev/mapper/centos_mric--srv2-root        52403200  5717192  46686008  11% /
devtmpfs                                  16378220        0  16378220   0% /dev
tmpfs                                     16388924       88  16388836   1% /dev/shm
tmpfs                                     16388924     9224  16379700   1% /run
tmpfs                                     16388924        0  16388924   0% /sys/fs/cgroup
/dev/mapper/centos_mric--srv2-home       433378560    32928 433345632   1% /home
/dev/sda1                                   508588   219764    288824  44% /boot
/dev/mapper/centos_mric--srv2-vm--images  67858700 16294864  51563836  25% /vm-images

> du -k /vm-images
16261904	/vm-images

But ls has it correct:

> ls -alt /vm-images
total 16261908
-rw-------.  1 qemu qemu 51547734016 May  9 15:15 centos7.0-1.qcow2
-rw-------.  1 qemu qemu 12887130112 May  9 15:15 centos7.0.qcow2
drwxr-xr-x. 21 root root        4096 May  9 15:13 ..
drwxr-xr-x.  2 root root          52 May  9 13:39 .

Any idea how I make this correct?

There are no side effects that I see but it is extremely puzzling to me 
as to why the new partition does not have the correct size. It appears 
the larger of the two VM images is not getting counted.

-- 
Paul (ganci at nurdog.com)
(303)257-5208