The tag has no wiki summary.

learn more… | top users | synonyms

8
votes
2answers
5k 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 ...
0
votes
2answers
2k 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.
0
votes
1answer
97 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) --> ...
0
votes
0answers
50 views

Xen blktap qcow/qcow2 not connecting

I have a similar issue as posted here, but with qcow/qcow2 images: Xen 4.1 host (dom0) with blktap disks ("tap:aio:") not connecting I tried Xen 4.1 on Ubuntu 12.04.04 precise, with both ...
2
votes
1answer
182 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 ...
10
votes
3answers
9k 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 ...
0
votes
2answers
122 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 ...
1
vote
0answers
115 views

qemu-img rebase operation taking longer than expected

#ls -1 Image1.qcow2 #qemu-img create -b Image1.qcow2 -f qcow2 Image1-DeltaFile.qcow2 Now I have an overlay called Image1-DeltaFile.qcow2. If I have another copy of Image1.qcow2 on a different ...
1
vote
1answer
205 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
votes
1answer
144 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
votes
1answer
200 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
votes
1answer
455 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? ...
0
votes
0answers
121 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: ...
3
votes
2answers
6k 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 ...
1
vote
2answers
505 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. ...
1
vote
3answers
894 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 ...
3
votes
1answer
133 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 ...
4
votes
2answers
1k views

mount qcow2 snapshots

I'm running some Xen-servers and started migrating to KVM. Currently my guests are either running on raw-images or LVMs. I found libvirt providing some very nice snapshot features (virsh ...
1
vote
1answer
624 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 ...
3
votes
1answer
618 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
votes
1answer
419 views

repartitioning a qcow2 image without data loss

I'm experimenting with repartitioning in a KVM virtual. I have created a new qcow2 disk and mounted in a virtual. I'm experimenting with resizing the filesystem and repartitioning. I had previously ...
0
votes
1answer
565 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
votes
1answer
870 views

kvm snapshot (libvirt)

Iam managing kvm by libvirt and using qcow2 file format. I can create snapshots of running wm with snapshot-create command, but if I transfer my qcow2 image to another host and define transfered host ...
2
votes
1answer
509 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 ...
1
vote
1answer
538 views

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 ...
0
votes
0answers
483 views

qemu-img: preallocate portion of qcow2 copy-on-write image?

I'd like to create a copy-on-write qcow2 image on top of a read-only base image. However, the write performance of the copy-on-write top image is too slow for the intended workload. Is there a way to ...
5
votes
2answers
6k views

Backup of KVM guests when using qcow2 disk files

I got a Ubuntu (hardy) system used for virtualization using KVM. Each guest got it's own qcow2 file used as disk. Guests are running Ubuntu (hardy). What would a good backup strategy be for such a ...
1
vote
1answer
2k views

How to mount/resize/modify LVM partition in KVM qcow2 or raw images?

I have KVM qcow2 and raw images. Virtual machines are partitioned with LVM. Now I want to resize the root partition of a few machines so I guess I have to do this from the host. My question is: how ...
1
vote
0answers
660 views

need some way to convert QCOW2 to OVF or open QCOW2 on WINDOWS

is there a way to convert QCOW2 to OVF? or is there a way to open an QCOW2 on WINDOWS (preferably free/open source)? the problem is that ubuntu's virtual machine manager was used to create the image ...
3
votes
1answer
14k views

How to convert a raw disk image to a copy-on-write image based on another image for use with kvm and virt-manager?

I have a virtual Windows machine running on kvm. Presently it has a 90GB raw disk image. I would like to clone this VM without having to keep two copies of the 90GB raw disk image around. It seems ...