Explore information related to virsh edit failed to get domain

Unable to allow access for disk path in libvirtd - Fix it Now

This article covers tips to fix the error Unable to allow access for disk path in libvirtd. By default, migration only transfers the in-memory state of a running guest (such as memory or CPU state). Although disk images are not transferred during migration, they need to remain accessible at the same path by both hosts.

To fix Unable to allow access for disk path in libvirtd error:

Set up and mount shared storage at the same location on both hosts. The simplest way to do this is to use NFS:

1. Set up an NFS server on a host serving as shared storage. The NFS server can be one of the hosts involved in the migration, as long as all hosts involved are accessing the shared storage through NFS.

# mkdir -p /exports/images
# cat >>/etc/exports <<EOF

2. Mount the exported directory at a common location on all hosts running libvirt. For example, if the IP address of the NFS server is, mount the directory with the following commands:

# cat >>/etc/fstab <<EOF  /var/lib/libvirt/images  nfs  auto  0 0
# mount /var/lib/libvirt/images

Read More

No guest machines present libvirtd - Fix it now

This article covers how to troubleshoot and fix No guest machines present libvirtd for our customers. 

The virsh program is the main interface for managing virsh guest domains. The program can be used to create, pause, and shutdown domains. 

It can also be used to list current domains. Libvirt is a C toolkit to interact with the virtualization capabilities of recent versions of Linux (and other OSes).

The libvirt daemon is successfully started, but no guest virtual machines appear to be present.

There are various possible causes of this problem.

Performing these tests will help to determine the cause of this situation:

1. Verify KVM kernel modules

Verify that KVM kernel modules are inserted in the kernel:

$ lsmod | grep kvm

If you are using an AMD machine, verify the kvm_amd kernel modules are inserted in the kernel instead, using the similar command lsmod | grep kvm_amd in the root shell.

If the modules are not present, insert them using the modprobe <modulename> command.

Note: Although it is uncommon, KVM virtualization support may be compiled into the kernel. In this case, modules are not needed.

2. Verify virtualization extensions

Verify that virtualization extensions are supported and enabled on the host:

# egrep "(vmx|svm)" /proc/cpuinfo

Enable virtualization extensions in your hardware's firmware configuration within the BIOS setup.

3. Verify client URI configuration

Verify that the URI of the client is configured as desired:

# virsh uri

How to fix No guest machines present #libvirtd #error:

After performing these tests, use the following command to view a list of guest virtual machines:

# virsh list --all

Read More

Troubleshoot KVM Virtualization Problem

This article covers how to troubleshoot KVM virtualization problem.

Log file locations and tools used to track down #KVM #problems are:
1. $HOME/.virtinst/virt-install.log – virt-install tool log file.
2. $HOME/.virt-manager/virt-manager.log – virt-manager tool log file.
3. /var/log/libvirt/qemu/ – Log files for each running virtual machine. If centos is virtual machine name, than log file is /var/log/libvirt/qemu/centos.log.

You can use the grep and other Linux tools to view this files:
# tail -f /var/log/libvirt/qemu/freebsd.log
# grep something $HOME/.virtinst/virt-install.log
$ sudo tail -f /var/log/libvirt/qemu/openbsd.log

Hyper-V backups can fail for any number of reasons, but there are some things to look for when backups don’t work the way that they are supposed to.
When backups fail, the first thing that you should do is to check the backup logs in an effort to learn more about the problem.
Specifically, you need to determine if the problem is confined to a particular host, a particular virtual machine, or perhaps related to the backup target itself.

Read More