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cache=none is probably not a good idea when you're using qcow2 files. A qcow2 file makes it appear that every access to the disk is fragmented. This means you get the random access performance of the drive every time and some flash drives are awefully slow (spelling intended) at random writes. Try with cache=unsafe (temporarily) to confirm this is the ...


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Qcow2 file backend can be significantly slow with cache=none setting. Moreover, "-o prellocation=metadata" preallocate metadata only, and actual file data will be fragmented. In other words, the qcow2 file remain a sparse one with only short stroke of allocation (for metadata). In the past a "-o preallocation=full" option appeared, by in recent qemu-img ...


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<disk type='file' device='disk'> <driver name='qemu' type='qcow2'/> <source file='/home/thomas/kvm/storage_pool/windows2012-test-3.qcow2'/> <target dev='vda' bus='virtio'/> </disk> This is what it should look like. BTW, yout NIC is also RTL and not virtio, tsk tsk tsk.


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The problem was using a disk image from DreamSpark/OnTheHub. I downloaded a new image, and it worked out of the box. The old image name was en_windows_server_2012_r2_x64_dvd_2707946.iso. I "ordered" a new free Windows Server 2012 of DreamSpark. I believe redownloading using Secure Download Manager will download the old image again, but I haven't tested ...


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This feature was requested a long time ago. Now libvirt supports it by providing two new commands: domifaddr and net-dhcp-leases Usage: domifaddr <domain> [interface] [--full] [--source lease|agent] Example outputs: virsh # domifaddr f20 --source agent Name MAC address Protocol Address ...


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Yes, all you need to do is take a snapshot of the disks while the VM is running and copy the backing image while the VM is running off the snapshot. To get rid of the snapshot live, you need to have a fresh version of libvirt and qemu, and you need to either execute virsh blockcommit or virsh blockpull, depending on whether you want the snapshot merged ...


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If the VM has lots of memory, saving it will in any case mean a large amount of time spent saving the memstate. If there is no hard requirement to backup a full VM state (because usually it is redundant, you'll get errors when you restore because of time differences, and it might even lead to a crash). Normally, VMs are backup up as following: Quiesce ...


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For your specific use case (base image + qcow2 overlay), the RAW format should be preferred: It's faster: as it has no metadata associated, it is as fast as possible. On the other hand, Qcow2 has two layer of indirection that must be crossed before to hit the actual data As the overlay layer must be a Qcow2 file, you don't lose the ever-useful snapshot ...



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