Questions tagged [qcow2]
76 questions
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Qcow2 backing image and overlay idea
I have 2 KVM servers running Windows Guests. I want to create a Qcow2 image with Windows 7 on it, install the base software needed, and then make that a backing image, read-only, with one qcow2 overlay on top which will be read write. I will take…
user160910
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1 answer
Managing qcow2 images with virsh
I have some qcow2 images which I am starting / stopping manually, with kvm, like this:
kvm -m 256 -smp 1 -drive file=/var/VMs/qcow2/server1.qcow2 -nographic -net nic,macaddr=52:54:00:11:34:55,vlan=0 -net…
![](../../users/profiles/91978.webp)
blueFast
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qcow2: Safe to use guestfish zerofree option on ext4 on top of LVM?
Is it safe to use guestfish's zerofree option on ext4 which is inside an LVM volume? If not, what is the best approach - rebooting (inside the VM) into recovery mode and using the regular zerofree utility? I am having trouble finding any references…
![](../../users/profiles/74317.webp)
BigChief
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Can't Recover Space from qcow2 image without deleting wanted snapshots
I have a virtual machine that started out with 5 snapshots 1,2,3,4,5.
I used qemu-img to delete snapshots 1,2,3. Snapshots 4 and 5 are still needed and were not deleted.
How can I release the space used by snapshots 1,2,3 and retain snapshots 4 and…
![](../../users/profiles/411200.webp)
user73383
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Mount qcow2 image on boot using fstab
I'm intending to make individual directories snapshotable in order to be able to experiment and rollback. Since there are many such directories and their contents can vary in size, solutions such as LVM or ZFS are not well-suited as they require to…
![](../../users/profiles/564958.webp)
Kalsan
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Noop convert qcow2 image but keeps internal snapshots
I have a qcow2 image. The image size is 200 GB, but the actual use is only 30 GB.
I'm using qemu-img convert -O qcow2 source.qcow2 shrunk.qcow2 to removes sparse space and the images shrinks correctly to 30 GB.
This image has internal snapshots…
![](../../users/profiles/622971.webp)
leanhtai01
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State of OCFS2 as KVM storage for QCOW2 format
Using a shared iSCSI SAN all SSD and good cluster aware filesystems are few and far between with Linux. What is the state of OCFS2 with modern Linux kernels and is it considered reliable enough to have 32 machines sharing the same volume in…
![](../../users/profiles/621476.webp)
pieterk
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Migrate ESXi vm to qcow2 with settings preserved?
I have attempted to export a vm in ESXi which produced 3 files:
vm_name.ovf (12KB)
disk-0-2.vmdk (73KB)
disk-1.vmdk (1.2GB)
I assumed the larger file (disk-1.vmdk) was the flat file and therefore uploaded that to an appropriate folder where I…
![](../../users/profiles/551465.webp)
MattE
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customize qcow2 ubuntu image fail
I download qcow2 ubuntu 18.04 img from here: https://cloud-images.ubuntu.com/bionic/current/bionic-server-cloudimg-amd64.img
I want to add some packages into qcow2 image before use it as a base img to create vms on it.
This command to update repos…
![](../../users/profiles/333559.webp)
Tuyen Pham
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Is there a way to convert qcow2 images to ovf format?
I have one qcow2 image. But, I need image in ovf format. I know there is already one answer here Any way to convert qcow2 to ovf?, but I don't have vCenter installed with me. So, i am looking for any linux utility or some other way to convert?
![](../../users/profiles/523042.webp)
pzk
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Which file has chaged from one VM-overlay to the next?
I've a base image of a windows10 machine.
[win10_base image].qcow2 -- [overlay_with_bug].qcow2
I have a bug of a app which I can reproduce. This bug does alter something on the system.
I want to reproduce the bug on a innocent windows VM. All…
![](../../users/profiles/448913.webp)
Cutton Eye
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Trim qcow2 disk
vps disk size does not updates on server when you delete files within vps.
For example one vps had 1TB usage, I deleted 800GB in that vps but vps disk size is still 1TB on server.
![](../../users/profiles/460013.webp)
Jevin Gala
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QEMU clarifications and setup optimizations
We are using qemu with kvm acceleration. I wanted to understand the -drive flag, currently we are using it as follows:
-drive file= if=virtio
I have the following questions
Clarification - I understand that this uses 'file' as…
![](../../users/profiles/218065.webp)
tsar2512
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Is it safe to use overlay as new VM from QCOW2 image for multiple users?
As title states, is it safe to give overlay of same image to multiple different users? From security standpoint, do they have access to other users data? Can any user corrupt/change base image or manipulate other user VM?
If it's not safe, is there…
![](../../users/profiles/421091.webp)
Trailo
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How slow can be a QCOW2 vm disk (proxmox/KVM) over NFS (dedicated 1Gbit)?
I'm running 3 proxmox 3.4 nodes using NFS shared storage with a dedicated 1GB network switch.
root@lnxvt10:~# pveversion
pve-manager/3.4-11/6502936f (running kernel: 2.6.32-43-pve)
root@lnxvt10:~# mount | grep…
![](../../users/profiles/333994.webp)
sgargel
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