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Questions tagged [qcow2]

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0
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0answers
13 views

guestmount: write in a VMDK are not saved after unmount

I have a VMDK and I mount it using the guestmount tool like so: # guestmount -a my-disk.vmdk -i --rw mount/ The VMDK filesystem is well mounted in the mount/ directory. I create a dummy file in the ...
3
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1answer
64 views

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 ...
2
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1answer
36 views

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 ...
0
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0answers
44 views

qemu-nbd mount windows parition

I'm currently trying to mount NTFS partition from a qcow2 image on Debian9. I tried with linguestfs and qemu-nbd, that's not working libguestfs but using qemu-nbd i can mount the qcow2 image on /dev/...
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0answers
28 views

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 ...
0
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0answers
630 views

Convert VHD with LVM to qcow2

I have cloudstack installation with XEN running as hypervisor and VM has vhd image format. My goal is to move VM to the KVM hypervisor and qcow2 image format. To convert from vhd to qcow2 I'm using ...
1
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1answer
26 views

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 ...
1
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2answers
534 views

How to replace of KVM image to other partition?

i have this structure of space of hdd-s: df -h Filesystem Size Used Avail Use% Mounted on udev 16G 0 16G 0% /dev tmpfs 3.2G 8.9M 3.2G 1% /run /dev/md2 ...
1
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1answer
191 views

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 ...
2
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1answer
762 views

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. ...
0
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1answer
1k views

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 ...
1
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1answer
213 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: ...
0
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1answer
144 views

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 ...
2
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2answers
1k views

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 ...
4
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2answers
5k views

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 ...
2
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1answer
2k views

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/...
0
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1answer
203 views

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?
3
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0answers
292 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 ...
1
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3answers
4k views

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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2answers
940 views

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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2answers
745 views

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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0answers
1k 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:~# ...
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1answer
2k views

(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 ...
5
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1answer
24k views

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-...
0
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1answer
1k views

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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0answers
167 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 ...
19
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2answers
67k views

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 ...
2
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1answer
1k views

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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3answers
4k views

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 (...
0
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2answers
2k views

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, ...
1
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1answer
825 views

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 ...
3
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1answer
13k views

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) --> ...
2
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1answer
439 views

OpenStack EC2 Ubuntu cloud image — SSH host keys were changed after emegency reboot

Recently one of our servers was hanged due to IPMI BMC failure. It is CentOS 6.3 OpenStack compute host serving KVM vitual machines with qcow2 backend. There was running a VM based on EC2 Ubintu ...
0
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2answers
828 views

qcow2 overlay growing too rapidly

virsh 0.10 I am using qcow2 overlay and a backing file, also qcow2. The overlay is growing way too quick, more than 20 GB in 24 hours, even though I am not writing very much to disk. Is this normal?...
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1answer
1k views

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 ...
0
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1answer
266 views

Mounting an LVM snapshot and converting file: is it safe?

I have KVM running and need to convert some qcow2 disk images from running guests into vmdk format. Is it safe to take an LVM snapshot of the logical volume that the qcow2 file resides on, mount it, ...
0
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1answer
600 views

Clone/Backup Strategy for VMs between ESXi and KVM requiring clones to run concurrently with original VMs

I am stuck on this problem and need help. ESXi Free version 5 and qemu-kvm/libvirtd version 0.10. I will put the TL;DR first since it captures the problem fairly well. TL;DR I have 2 VMs on a KVM ...
0
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1answer
1k views

Qcow2 converted to vmdk show as spare and can't be snapshot

As the title says, kvm disks that I converted and moved to ESXi are useless because I cannot use snapshots due to the fact that they are sparse disks. Does anyone have a resolution for this issue? ...
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0answers
1k 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: ...
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2answers
2k views

How safe is it to access qemu/kvm raw or qcow2 disk image files from host

I've read mixed opinions about how safe it is to modify qemu disk image files. There are two distinct situations I'm interested in. 1) let's take a raw or qcow2 disk image file not used by kvm (i.e. ...
3
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1answer
171 views

How to distinguish between virtual disk image formats?

There is huge number of different formats for virtual storage files for desktop and server purposes (vmdk, qcow2, vdi, vdk, etc.). I'm writing a little script for manipulating them and would like the ...
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4answers
4k views

DRBD & KVM replication is possible?

i have two KVM servers with some virtual machines. Server (A) KVM with qcow2 images Server (B) KVM mount NFS for partiton (with qcow2 images present on server A). My question is simple, what is the ...
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2answers
14k views

Is there any way to shrink qcow2 image without converting it raw?

Is there any way to shrink qcow2 image without converting it raw? I cannot convert it to raw because I don't have disk space enough for raw image.
4
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2answers
16k views

conversion of a VMDK image with qemu-img failed with “error while reading sector 131072: Invalid argument”

I tried to convert a VMDK image found in a OVA file to the QCOW2 format with the qemu-img command but it failed with the error message qemu-img: error while reading sector 131072: Invalid argument ...
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6answers
50k views

Incredibly slow KVM disk performance (qcow2 disk files + virtio)

I'm having some serious disk performance problems while setting up a KVM guest. Using a simple dd test, the partition on the host that the qcow2 images reside on (a mirrored RAID array) writes at ...
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1answer
4k views

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 -...
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4answers
2k views

Do I need to zero-fill a qcow2 image before compacting it?

I want to recreate a dynamically allocated qcow2 image in order to shrink it. Is it sufficient that all unnecessary files have been deleted, or do I also need to fill the space formerly occupied by ...
0
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1answer
764 views

More than one clone of xp qcow2 base image using kvm gives missing hal.dll error

I am running linux mint debian edition. I have kvm installed and working, using virt-manager as the manager. I have a qcow2 disk file with windows xp pro installed that I used as a base to clone a new ...
2
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1answer
710 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 ...
18
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3answers
31k views

free up not used space on a qcow2-image-file on kvm/qemu

we are using kvm/qemu with qcow2-images for our virtual machines. qcow2 has this nice feature where the image file only allocates the actually needed space by the virtual-machine. but how do i shrink ...