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11

TRIM works at the filesystem level so as you're giving your KVM domains a raw block device then you need to enable TRIM from within the domain; your host can't know the domains filesystem utilisation without examining it. To enable this you need to ensure there's a discard='unmap' attribute added to the disk definition in the XML for the domain, this is ...


7

I still don't understand why /22 instead of /23 Because you have calculated your subnets wrong, and you are trying to use IPs from two different subnets. Or to put it a different way, if you use a /23 bit mask your starting address for the range, must be the first address for that range. 192.168.1.1 is not a starting address for any network described ...


7

If you don't want to do any configuration inside the guest, then the only option is a DHCP server that hands out static IP addresses. If you use bridge mode, that will probably be some external DHCP server. Consult its manual to find out how to serve static leases. But at least in forward modes nat or route, you could use libvirt's built-in 'dnsmasq' (More ...


6

This is for google guys like me. Those answers are pretty useless, this is not a distro problem but a bug in Windows: http://keyliner.blogspot.se/2009/11/windows-7-slow-keyboard-response.html (second clause) That is what helped me: a. Start, Run, "Regedit" If the RUN command is not visible, see this link. b. Tunnel to this key: ...


4

When the user's home directory is encrypted with ecryptfs sshd cannot read the authorized_keys file from the user's home directory before the home directory has been mounted. During login sshd will use pam to authenticate the user, and pam will use the password entered by the user to mount the encrypted home directory. This is problematic if you want to ...


4

So I'm managed to run the nested Hypervisor inside KVM and it turns out to me that the Red Hat Kernel 2.6.32 did not support the nested keyword when it was passed using kvm-intel.nested=1 so that is the reason there was no file such as /sys/module/kvm_intel/parameters/nested It worked for me in kernel 3.10 I installed it set the nested parameter. ...


4

Disclaimer: I work for Red Hat but have no idea about the decisions related to this particular bug. I made a request, though, and the bug is now public. The short version is: passthrough seems to have a lot of bugs in different situations, none of them simple fixes, and it (again, really not speaking officially here) seems like it was judged to not really ...


4

The Problem I've got the same problem and I haven't found a good solution. Here's what I found: The problem is that after resume, the system and hardware clock times on the guest are different: root@guest:~# date; hwclock Sat Oct 11 13:09:38 UTC 2014 Sat Oct 11 13:10:42 2014 -0.454380 seconds On the host, they agree: root@four:~# date; hwclock Sat ...


4

No, it doesn't work like that. Among the reasons is that for a single thread, you can never get more than the 2 GHz clock speed one single core offers and virtualization is no trick around this fundamental restriction.


4

While it might not look like one, Hyper-V actually is a type-1 hypervisor, because the virtualization layer is placed below the Windows operating system and mediates all hardware access (some time ago, before hardware-assisted virtualization improved a lot, it was very common to experience really slow graphic performance on Hyper-V hosts, due to the O.S. ...


3

To change the state of the network link for a KVM guest it would be much better to use the appropriate tool, i.e. the hypervisor virsh domif-setlink domain interface-device state Modify link state of the domain’s virtual interface. Possible values for state are "up" and "down". If --config is specified, only the persistent configuration of the ...


3

On my RHEL6 and CentOS6 that is established by creating a symbolic link to VM XML description in /etc/libvirt/qemu/autostart/ : ls -la /etc/libvirt/qemu/autostart/ total 4 drwxr-xr-x. 2 root root 4096 Dec 19 2012 . drwx------. 4 root root 4096 Dec 21 08:50 .. lrwxrwxrwx. 1 root root 29 Mar 3 2012 hosting2.xml -> ../hosting2.xml lrwxrwxrwx. 1 root ...


3

After verifying base guest configuration file (xml) found the problem. <vcpu placement='static' cpuset='2'>1</vcpu> Since I used same template for creating all VMs after cloning, all VMs were using same CPU.


3

To grant permanent access to the raw USB device nodes to the user the hypervisor runs as, you need to create an udev rule; the chown-based answer will only work until the next reboot. In /lib/udev/rules.d, create a file like 51-usb_passthrough.rules : SUBSYSTEM=="usb", ENV{DEVTYPE}=="usb_device", ATTRS{busnum}=="2" ATTRS{devpath}=="1" GROUP="kvm" Here I ...


3

As you are using Openstack, when you create a flavour you can specify the rxtx_factor. My understanding is that this is used to calculate a percentage of the rtx_cap on the network that is available to the VM. I'm not sure if all hypervisors will support it however, though so you may need to do some additional digging to see if KVM does.


3

You need to specify a valid URI for the migration to be successful. What kind of transport is available depends on your setup, but try qemu+ssh://10.8.1.9.


3

Set the wanted disk as virtio-disk0, with target of /dev/vda. The order the disks appear in, in the XML is also important, so make sure the OS disk comes first


3

I got so inspired by kasperd's idea yesterday that I made this: https://github.com/bjornnorman/decryptfs-ssh I've tried it out a little already and it seems to work brilliantly. It makes it really simple to add/remove keys for passwordless decryption of ecryptfs home folders when using SSH... Like kasperd's original, it hasn't been exposed to a peer ...


3

Check that the kernel is set to enable IP forwarding: sysctl -a | grep forwarding You can enable with: sudo sysctl net.ipv4.conf.all.forwarding=1 sudo sysctl net.ipv6.conf.all.forwarding=1 There may also be an issue with ARP proxying. Check with: sysctl -a | grep proxy_arp And set with the command: sudo sysctl net.ipv4.conf.eth0.proxy_arp=1 You ...


3

I would say you have a lot more to consider than just hard drives. You are intending to transfer to a completely different virtualization package, which will take much more than a days worth of work. Theoretically you would need to: - Transcribe the VM configurations (more than likely by hand) from Microsoft's spec to QEmu's spec. - Convert the VHD images ...


2

...fortunately the process is pretty straightforward. Prerequisites/preparation In order to increase cpu count during runtime you need to configure the VM to have a "maximum" vcpu count and a lower "current" cpu count. An example xml extract (modify using virsh edit ): <vcpu placement='static' current='4'>16</vcpu> Perform the increase ...


2

As Michael Hampton suggested, instead of using KVM directly use virsh, which simplifies handling virtual machines (not only KVM) a lot. As root, first install the needed packages: apt-get install virtinst libvirt-bin You might want to have network-access on your guest machine you will need to have to create a bridge interface on your Host-system (let's ...


2

As far as I know this is not yet supported. When necessary, I work around it by connecting to the Windows VM via RDP (in my case using Remmina, but you can use whatever you like).


2

VNC has no facility for clipboard passthrough. You might want to try spice, with the proper agents it works quite well.


2

All of the "extra" rules you are seeing were added by the libvirt daemon to support (and secure) virtual networking for your virtual machine guests. You generally do not need to worry about these rules (and should not try to persist them, as then they would be duplicated at next boot). It's also clear that all of your persistent firewall rules were added to ...


2

You should set up an LVM filter on the host, to filter out the unwanted LVM devices detected. Here's a link to the official documentation: http://www.centos.org/docs/5/html/Cluster_Logical_Volume_Manager/lvm_filters.html something like filter = [ "r|/dev/VM_related_VG/*|" ] should work


2

Since KVM is a part of Linux, any Linux based monitoring solutions will work, from the standard nagios checks to proprietary hardware health monitoring solutions, like Dell OMSA. RHEV will monitor the hosts' health, keep the VMs working and make sure all hosts can access all the required cluster resources, but it is not meant to monitor hardware level ...


2

PXE has a bunch of benefits: Works on real servers as well as virtual ones without changing anything, so you need to set-up the infrastructure only once. It's easy to automate installations from start to finish (technically possible with DVDs but usually requires more work) Once you have the infrastructure set-up, adding a new version of your distribution ...


2

Yes -- there is an issue with that kernel. We had the same problem running multiple java instances on a dual E5-2687. Never ran out of memory, but after a few hours of load it would crash if we tried to ssh in or run ps. Dmesg showed the same error you have: kernel BUG at /build/buildd/linux-3.13.0/mm/memory.c:3756! We installed the latest testing ...


2

virt-sparsify can do all this with less hassle on your part: http://libguestfs.org/virt-sparsify.1.html



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