Questions tagged [qcow2]
The qcow2 tag has no usage guidance.
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After converting Windows guest OS .vmdk file to .qcow2 and hosting to KVM gives "No Bootable Device"
We are migrating guest VM from VMware 7 to KVM (installed on Ubuntu 22.04 LTS).
We have achieved success in migrating all Ubuntu guest VM from VMware to KVM by converting the vmdk disk to qcow2.
...
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KVM - Reduce Storage Size of QCOW2 File To Specific Size
I want to reduce the storage size of the VM's running on a Linux 8 physical machine from 2 TB to 400 GB. The actual size of VM's is around 100 GB. But the space we give it as allocated size is too big ...
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How is this even possible?
This must be a glitch in the Matrix. Right? Let me explain.
I have some automation that converts a qcow2 image into a raw image before uploading the resulting raw image to an S3 bucket (in AWS). ...
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611
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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 ...
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What capabilities do you lose when turning off COW on a qcow2 file?
I run a small internal cloud utilizing 3 redundant, live migration capable Ubuntu/Qemu/KVM hosts with ~30 mixed OS VMs.
The Pool volumes are BTRFS and before any of you give me crap about it: this is ...
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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 ...
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2
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Incremental backup qcow2 image with rsync
I use rsync to backup the qcow2 disks of my virtual machines. However, I would like to be able to get an incremental backup so that I don't have to copy the entire disk every time.
for now I use rsync ...
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519
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OVA to QCOW2 conversion - Openstack instance dracut initqueue timeout and could not boot
I have a custom OVA built with Centos 7 and trying to convert it to qcow2.
I have extracted the files from the OVA and converted the vmdk to qcow2 with following command:
qemu-img convert -O qcow2 ...
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How to enable zstd for your qcow2 files [closed]
In QEMU 5.1 zstd compression of your qcow2 files was introduced but I can't find a way to activate it?
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354
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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 ...
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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 ...
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How do I make a compressed disk image (qcow2 and/or squashfs) from a disk directly?
I have a disk attached to my server and I want to make the disk image of it downloadable on the same server. The disk itself is 500GB but I don't want to have a 500GB disk image for download. I'd like ...
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2
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933
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Terraform Libvirt - How to use local qcow2 file in the hypervisor instead of cloud images?
It seems like the libvirt provider only takes pre-defined cloud images. I create my own base qcow2 image that is local to the hypervisor and wish to use it as source file with terraform libvirtd.
Is ...
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2
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764
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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 ...
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902
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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 ...
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How to check the cache mode of a qcow2 image?
Say I converted an image to writethrough cache mode with this command:
qemu-img convert -t writethrough -O qcow2 in-image.qcow2 out-image.qcow2
How can I check/verify the cache mode of the image?
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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 ...
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504
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qcow2 image: ERROR refcount block 69 is outside image
I have this backup.qcow2 image which was working fine in my kvm/qemu virtual machine before.
When I attach it to another virtual machine, Windows recognizes the disk but fails to read partitions. The ...
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Convert QCOW2 to VMDK (Citrix Xen)
Hy everyone,
the search function does not come up with a propper solution.
I want to convert a old KVM disk QCOW2 to an compatible Ctrix Xen disk e.g. VMDK with that qemu-img converting tool
qemu-...
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2
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193
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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 ...
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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.
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Ansible fails at "Gathering hosts" presumably because SSH is slow to connect. Setting `UseDNS no` resolves the issue
I am having what appears to be a DNS related issue that I would appreciate some assistance resolving.
I'm using Ansible to provision a Kubernetes cluster on my Proxmox server. The project works in ...
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259
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xfs_db reports high file fragmentation where VM is located, but VM shows almost no fragmentation
I have several libvirt VMs stored on xfs partitions and am using gluster to replicate the storage. The VMs use qcow2 for storage.
Some of the partitions where the VMs are located indicate high file ...
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45
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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=<qcow2 snapshot file> if=virtio
I have the following ...
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KVM file size issue on RHEL 6.9
I tried to allocate 60GB of additional storage to my Win7 KVM by adding a new disk under 'Hardware Settings' using Add Hardware. But the new disk didn't show up in Win7 so i deleted the Disk using ...
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3
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16k
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How to move KVM image to another directory/partition?
My storage devices are mounted as follows:
$ df -h
Filesystem Size Used Avail Use% Mounted on
/dev/md2 193G 35G 148G 19% /
/dev/md4 492G 73M 466G 1% /mnt
My KVM image is ...
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621
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How do Centos cloud images map to iso images
Is it possible to figure out which cloud image maps to which iso release for Centos.
I would like a Centos 7.3 minimal image, but when I browse the Centos cloud image site I cannot see any references ...
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KVM snapshotting. How to see what's inside the qcow2 file?
I use qcow2 file format and create snapshots using a Virt-manager GUI.
I assume I have 100GB disk space and 70% is used by VM at this moment. The qcow2-file size is about 70GB. I create a snapshot. ...
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2
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KVM guest qcow2 larger than disk size
I have a Windows 10 VM running on a server that I need to move to another server. The trouble is that the qcow2 file size is too large for the target server.
What's odd about this is that the ...
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363
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Cannot upload file to qcow2 image file using guestfish on rhel 7.3
I am trying to write a temp file into a qcow2 image file using guestfish as follows:
[root@localhost home]# guestfish --rw -i -a vm.qcow2 upload temp /home/
and faced the following problem:
...
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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 ...
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qemu-img convert CentOS7 vmdk to qcow2 and vice versa error
I'm trying to convert CentOS7 from VMDK to QCOW2 and vice versa using qemu-img convert command.
when uploading the new Templates (OVF with the new converted vmdk and KVM template with the new ...
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How to repair a broken-resized qcow2 disk image for libvirt/kvm?
Today I wanted to increase the size of a VM, so I did what I always do (have done it before):
qemu-img resize diskimage.qcow2 +22GB
Then the file broke and the VM does not start any more. I tried ...
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How to create a qcow2 file that is not thin provisioned?
When I do the below then the qcow2 file is less than 200KB.
# qemu-img create -f qcow2 /var/lib/libvirt/images/urb-dat0.qcow2 10G
# du -hsc /var/lib/libvirt/images/urb-dat0.qcow2
196K /var/lib/...
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Is it safe to use fallocate --dig-holes while being modified
Is it safe to use fallocate --dig-holes on a file while it is being modified/written? For example on a QCOW2 image opened by a KVM guest?
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Creating OVF headless with generated vmdk
I am looking to create an OVF file during a nightly build process. I currently have this process creating a qcow2 image, which I convert to vmdk using qemu.
qemu-img convert -f qcow2 ${image_name} -O ...
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QCOW2 virtual size lowering
I'm trying to get the virtual size of a qcow2 container down so that it can fit in a openstack flavor with 10GB disk.
root@node-10:~# qemu-img info zztop.qcow
image: zztop.qcow
file format: qcow2
...
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Accessing linux guest OS filesystem in qcow2 image
I'm attaching VM qcow2 image to get access to files which inside:
modprobe nbd max_part=63
qemu-nbd -n -c /dev/nbd0 /var/lib/libvirt/images/vm-image.qcow2
scanning for volume groups vgscan:
...
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qemu-img: Could not open '/dev/stdin': Could not refresh total sector count: Operation not permitted
I want to transfer block device contents over the network directly into a qcow2 image. I started with a small simulation:
[root@okvmh1 default]# dd if=/dev/zero bs=1M count=100 | qemu-img convert -p -...
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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:~# ...
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(centOS) cloud-init not pulling ssh
Trying to build CentOS 6 qcow2 image with OpenStack guide[http://docs.openstack.org/image-guide/content/centos-image.html].
I'm using "cloud-init" instead of the "/etc/rc.d/rc.local" script but I ...
user192756
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How do you create a qcow2 file that is small yet commodious on a Linux server?
I believe that there are qcow2 files that displace a small amount of gigabytes on a server (as verified with a df -h on the physical server) yet allow for lots of space when you log into the virt-...
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Edit /etc/resolvconf/resolv.conf.d/base in Centos 7 -- qcow2 image
My qcow2 image uses local nameserver, 192.168.122.1 which is not working for reasons unknown.
So, I tried to use guestfish and edit the file /etc/resolv.conf to add nameservers, 8.8.8.8. This doesnt ...
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Boot a qcow2 image in Ganeti
I am very confused on how Ganeti actually boots machines. My problem is quite simple.
I have a qcow2 image in a machine and I want to boot it. How can I do it? I don't really understand the idea of ...
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Which is better image format, raw or qcow2, to use as a baseimage for other VMs?
I am using a baseimage and based on that creating many VMs. And now I want to know which is better, qcow2 or raw to use for a baseimage. Moreover, can you please tell me if there is any advantage of ...
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How to backup running KVM guest qcow2 disk without LVM?
How to backup running KVM guests, when using qcow2 disks and host system does not use a LVM? Is it even possible without guest shutdown?
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5
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10k
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KVM virt-clone while the VM is running
Is it possible to clone a running kvm machine without tools like virt-clone?
They already have the original vm in production, I cannot shut it down. If I don't care about temporary data corruption (...
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How do I make KVM images with LVM partitioning be thinly provisioned with a max growth size?
BACKGROUND: Up to now, I have been provisioning VMs as follows:
Create template/gold VM:
Create new CentOS 6.6 VM with raw 200GB disk (1 .xml file, 1 .img file)
LVM partitioning with: /boot, swap, ...
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Qcow2 images growing far beyond what they should
I am using ubuntu 12.04 and have seen this: https://bugs.launchpad.net/ubuntu/+source/qemu-kvm/+bug/1025244
Our qcow2 images are growing far beyond what they should... with some of them growing to as ...
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Any way to convert qcow2 to ovf?
In our application we are downloading a qcow2 image and after that we are supposed to import that as OVF.
So any way to convert qcow2 --> OVF or qcow2 --> vmdk(using qemu-img convert) --> ...
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