Questions tagged [qcow2]

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How can I recover the space in a qcow2 file after deleting snapshots, while retaining remaining 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 ...
user73383's user avatar
3 votes
0 answers
830 views

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 ...
Shayne's user avatar
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3 votes
0 answers
3k views

qcow2 Disk size much bigger than virtual size

What would cause this? ls shows the qcow2 to be 241G, in the VM it only has ~ 160 GB drive, no unpartitioned space. Win 7 VM, Host = EXT4 2.6 Kernel virsh 0.9.10 file format: qcow2 virtual size: ...
user avatar
2 votes
1 answer
789 views

Ubuntu Server mdadm drbd ocfs2 kvm hangs under heavy file reading

I have deployed four ubuntu 10.04 server. They are coupled two by two in a cluster scenario. on both sides we have software raid1 disks, drbd8 and OCFS2 and on top of it some kvm machines run with ...
Stefano Annese's user avatar
1 vote
1 answer
757 views

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 ...
user73383's user avatar
1 vote
0 answers
210 views

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 ...
Kalsan's user avatar
  • 131
1 vote
0 answers
248 views

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 ...
pieterk's user avatar
  • 111
1 vote
0 answers
241 views

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?
Mike's user avatar
  • 598
1 vote
1 answer
592 views

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 ...
JanPl's user avatar
  • 111
1 vote
1 answer
2k views

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-...
rcpe's user avatar
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1 vote
1 answer
387 views

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: ...
user3460393's user avatar
1 vote
0 answers
279 views

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 ...
Anastasios Andronidis's user avatar
0 votes
0 answers
74 views

Can qcow2 overlay get committed back into raw backing file?

I am trying to design a system utilizing the btrfs filesystem and libvirt. btrfs has copy-on-write (COW) already, it's very easy to do snapshots and it's very efficient to transfer the snapshot to a ...
Wang's user avatar
  • 322
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0 answers
356 views

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. ...
AM2023's user avatar
  • 1
0 votes
1 answer
606 views

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 ...
rndm_acct1's user avatar
0 votes
1 answer
669 views

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 ...
Sandeep's user avatar
  • 121
0 votes
1 answer
2k views

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 ...
CosmoΓammaByte's user avatar
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0 answers
144 views

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.
Jevin Gala's user avatar
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0 answers
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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 ...
tsar2512's user avatar
  • 121
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0 answers
2k views

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:~# ...
sgargel's user avatar
  • 202