• Linux How To Add User To Additional Group


    sudo usermod -a -G groupname username It's really simple like above, the -a is for append so that you are not changing their main group, but adding them to another additonal group. Just change "groupname" to your group and "username" to the user you want to be added to "groupname". A common task these days is getting your user access to kvm for virtualization so the KVM/QEMUprocess........
  • KMODE EXCEPTION NOT HANDLED - QEMU/KVM Won't Boot Windows 2016 or 10 Image or Physical Machine


    This should work but the key thing is having the "-cpu host" flag. Once you add the correct -cpu host flag then it should boot just fine on KVM. qemu-system-x86_64 --enable-kvm -cpu host -smp 8 -m 8192 -drive format=raw,file=the-file.img Examples can be found here on how to boot Windows properly with KVM.........
  • qemu-kvm error "Could not initialize SDL(No available video device) - exiting"


    Now older versions of qemu-kvm didn't throw this error say if you just had "-video cirrus" when starting qemu-kvm. But newer versions do care. And this probably only applies to you if you are running from bash/terminal with remote kvm images. What you need to do is remove the "-video" part and just add -vnc :5 eg. this would fix the error: qemu-system-x86_64 -enable-kvm -boot order=cd,once=dc -m 1024 -drive........
  • QEMU-KVM won't boot Windows 2016 or 2019 server on an Intel Core i3


    CPU:Intel(R) Core(TM) i3-2120 CPU @ 3.30GHz MOBO: Manufacturer: ASUSTeK COMPUTER INC. Product Name: P8H61-M LX3 PLUS R2.0 qemu-kvm-0.12.1.2-2.506.el6_10.1.x86_64 This is weird but the only OS I've found this machine doesn't work with is Windows 2019 Server. Ihave no idea, when 2008, 2012 work f........
  • Cisco Unified Communications Manager / CUCM IP 8.6,10,12 Install Error Solution


    Install Errors on Version 12: This error happened on QEMU emulator version 2.11.1 pve-qemu-kvm_2.11.1-5 on Proxmox/Debian but installing on QEMU.12 on Centos 6 did not produce the error. *Update it is not related to the OS or QEMU version. This happened in Centos 6 too after a second install. What really causes this even though you successfully install........
  • Cisco Unified Communications Manager 12 Install Errors on Proxmox/KVM


    The strange thing is that usually the first install or two will work on any new machine but then it suddenly won't. I had this experience on QEMU 2.13 on a different machine. There is something finicky or buggy about the CUCM installer even when choosing the same virtual hardware specs. qemu-kvm command: /usr/libexec/qemu-kvm -version QEMU PC emulator version 0.12.1 (qemu-kvm-0.12.1.2-2.506.el6_10.1), Copyright (c) 2003-2008 Fabrice Bellard ........
  • Local Vs Universally Administered MAC Address NIC Refuses to come up


    2,6,A or E is what the second digit of your MAC address must be otherwise a lot of OS's will not work. They will say the NIC is down/not connected even though it is. This is because if the second digit is not set properly it will not view as a valid MAC or device uplink. This is especially an issue with VMs whether in QEMU etc.. if you are making your own MAC. MAC address is invalid c4:d1:aa:e5:10:05 To fix it just........
  • Linux qemu-kvm How To Enable Soundcard in Guestl


    Pass QEMU this flag: -soundhw ac97 Or you could use (for a Ensoniq soundcard): -soundhw es1370 However on some machines I get this error: pulseaudio: pa_simple_new for capture failed pulseaudio: Reason: Connection terminated pulseaudio: pa_simple_new for capture failed pulseaudio: Reason: Connection terminated audio: Failed to create voice `ac9........
  • QEMU-KVM Windows and Server Guest Installs Mouse Tracking Pointer Location Solution


    You may have noticed if you are running QEMU/KVMmanually that in Windows the the position of the physical mouse does not match where the mouse is positioned within Windows. There is an easy command to pass to qemu-kvm or qemu-system (whatever you call your binary): -usbdevice tablet The above flag will fix your mouse pointing problems whether you are running Windows 95, 98, NT, XP 2000, 2003, Vista, 7, 8 10 or Server 2000, 2003, 2008, 2012, 2016 or 2........
  • qemu-kvm qemu-system Image format was not specified for '/mnt/space/cucm12.img' and probing guessed raw. Automatically detecting the format is dangerous for raw images, write operations on block 0 will be restricted. Specify the 'ra


    WARNING: Image format was not specified for '/mnt/space/cucm12.img' and probing guessed raw. Automatically detecting the format is dangerous for raw images, write operations on block 0 will be restricted. Specify the 'raw' format explicitly to remove the restrictions. #you should manually specify the format q........
  • How To Boot Cisco CUCM UCSInstall 8.6, 10, 11 and 12 on KVM/Proxmox


    The key thing is that you must use a "machine"id of "pc-1.3" or it will say your hardware is not supported. Additionally you MUST use a virtio disk or you will get a ks_pre.sh error as soon as the install starts (a look at logs will show it can't find a disk). This is funny because even though the OS finds the disk and an fdisk -l shows it, it looks like the script looks for a /dev/vda device (virtio) and nothing else, so if you didn't use Virtio as you........
  • VBOX VirtualBox How To Import Raw .img Disk File


    What you need to do if you have taken a dd or real raw image dump of a hard disk: VBoxManage convertdd windows2019-eval-template.img windows2019.vdi --format VDI The .img is the raw dd dump and the .vdi is the output file. --format VDIspecifies to output to .vdi format If you are in a pinch you can always use qemu-kvm binary and manually specify the .img as your disk and i........
  • Proxmox Breaks Storage/LVM Backing If Killing QEMU-IMG


    I tried to stop a qemu-img copy or clone and it broke everything. It was fine to "stop" it from the GUI but a process still persisted so I killed the relevant qemu-img and the kernel went crazy. It also may not have helped that I tried to lvremove a different volume (an unused disk). But either way it breaks LVM (you cannot even run lvdisplay) so a reboot is necessary. Jan 17 06:45:21 testserver kernel: [ 5680.439337] systemd-udevd D 0&nbs........
  • Proxmox trying to acquire lock... TASK ERROR: can't lock file '/var/lock/qemu-server/lock-102.conf' - got timeout


    If Proxmox won't start aVM with an error like this: trying to acquire lock... TASK ERROR: can't lock file '/var/lock/qemu-server/lock-102.conf' - got timeout rm /var/lock/qemu-server/lock-102.conf Then try to restart the VM and it should be good.........
  • QEMU / KVM How To Manually Create Basic Virtual Machine VM


    1.) Create Image using qemu-img qemu-img create -f qcow2 skype.img 40G 2.) Start VM using flags -m = memory in MB -drive file=yourimagefile.img -cdrom /path/to/the.iso qemu-system-x86_64 -m 4096 -drive file=skype.img -cdrom ~/Downloads/SfB-E-9319.0-enUS.ISO Enable Bridged Networking........
  • hwloc-nox set CPU affinity in Linux


    sudo apt-get install hwloc-nox Reading package lists... Done Building dependency tree Reading state information... Done The following NEW packages will be installed: hwloc-nox 0 upgraded, 1 newly installed, 0 to remove and 530 not upgraded. Need to get 151 kB of archives. After this operation, 453 kB of additional disk space will be used. Get:1 http://archive.ubuntu.com/ubunt........
  • qemu-img resize howto


    The Correct Way To Resize In Place qemu-img resize kvmuserwindows2008dcetest.img +1G Image resized. Below is a common mistake that some users make they are trying to specify a new image name but it can be resized in place (just make sure the VMis NOT running and you've backed up the data in case something goes wrong). qemu-img resize kvmuser453111.img kvmuser453111-larger.img +5G New i........
  • How to qemu-kvm enable bridged networking in Debian Ubuntu Linux Mint on KVM containers


    I've read a few guides about this but they didn't work for me. sudo apt-get install bridge-utils #don't think the above is enough it won't work still even though you have by default an /etc/qemu-ifup that handles it if you have the right tools and setup sudo qemu-system-x86_64 -net tap -net nic -enable-kvm -cpu host,vmx=on ~/VirtualBox VMs/vsphere-vcenter/vsphere-vcenter.vdi W: /etc/qemu-ifup: no bridge for guest interface foun........
  • VirtualBox Nested Virtual Machine Containers with KVM Not Working no SVM or VMX module in the guest


    I can't get vmx cpu extensions to show up in Virtualbox guests despite enabling nested paging and enable vmx in virtualbox guest but this doesn't help that you check VT-X or the AMD Virtualization SVM it enables it for the guest to use BUT does not pass it through. This means if you check cat /proc/cpuinfo in the guest you will see the CPUdoesn't support virtualization. It looks like VirtualBox still hasn't implemented this! But there is good news I&n........
  • PYCURL ERROR 22 - The requested URL returned error: 404 Not Found Solution


    # yum -y install qemu-kvm Loaded plugins: fastestmirror Setting up Install Process Loading mirror speeds from cached hostfile * base: mirror.lzu.edu.cn * elrepo: ftp.utexas.edu * epel: ftp.jaist.ac.jp * extras: mirrors.aliyun.com * openvz-kernel-rhel6: mirror.fdcservers.net * openvz-utils: mirror.fdcservers.net * updates: mirrors.nwsuaf.edu.cn Resolving Dependencies........
  • KVM/QEMU how to boot from direct kernel vmlinuz and initrd with networking


    Thsi is very handy when doing your own kernel development. -m specifies how much ram (in the example it is 768MB) -kernel specifies the path to the kernel file -net tap,ifname=tap1,script=no (the ifname=tap1 is what you need to change and setup manually). *Run "tunctl -b" to create a tap device and use the one it gives you for ifname= Enable networking to the outside like this: *Note we assume that your bridge is br0 i........
  • libguestfs tools howto guide for mounting partitions and managing virtual machine images


    libguestfs tools howto guide for managing virtual machine images. libguestfs-tools aka guestfs tools has a lot of tools that make this very easy for you. You can easily mount partitons from an image with some of the commands below. To mount a partition #mount the kvmuser102821.img image and the /dev/sda1 partition from it to the local directory "mount" guestmount -a kvmuser102821.img -m /dev/sda1 mount ........
  • kvm centos cannot compile error


    ./configure ./configure: cannot locate gcc 3.x. please install it or specify with --qemu-cc yum -y install gcc make ./configure ./configure: cannot locate gcc 3.x. please install it or specify with --qemu-cc yum -y install compat-gcc-* ./configure Error: Could not find alsa Make sure to have the alsa libs and headers installed. yum -y install alsa-lib-devel ./configure........
  • qemu-img KVM create disk image howto


    qemu-img create -f qcow2 isotest.qcow2 10G The above creates a "qcow2" format image called "isotest.qcow2" that is 10GB in size. If you want to preallocate all of the space for increased performance do this: qemu-img create -f qcow2 isotest.qcow2 -o preallocation=full 10G It is controlled with the preallocation=full option, of course by default this is set to off........
  • KVM support Ubuntu 12.04 or 12.10


    This seems to be a verified bug on KVM with no solution. I wasn't able to get through the installer with Ubuntu 12.04, it would crash while "configuring apt". I was able to install it with Ubuntu 12.10 but it crashes randomly at times. This happens with the latest Centos 6.3 kernel and KVM package, I even compiled the latest version from the KVM website and used that, but the results are still the same. Here's some links to discussion about the bugs:........
  • How to convert raw,img,vdi,vmdk and other virtual image formats using qemu-img convert between VBOX/KVM/VMWare/Xen


    The example below converts youvm.img into a vdi. The -O vdi specifies the new format will be vdi but you can use any other valid formats/vice versa. qemu-img convert yourvm.img -O vdi yourvm.vdi This is very handy for those who need to switch between virtualization technologies.........
  • KVM compilation issue/solution - Disabling PIE due to missing toolchain support glib-2.12 required to compile QEMU


    qemu-kvm-1.2.0]# ./configure Disabling PIE due to missing toolchain support glib-2.12 required to compile QEMU Solution install glib2 *Don't confuse glib2 with glibc, they are different and it may catch some off guard. yum -y install glib2* After that KVM should compile and install just fine.........
  • KVM/QEMU Base/Template Images and the power they provide


    qemu-img create -b centos.5-8.x86.20120308.qcow2 -f qcow2 ../kvmguests/25000-centos5.8x86.qcow2 Formatting '../kvmguests/25000-centos5.8x86.qcow2', fmt=qcow2, backing_file=centos.5-8.x86.20120308.qcow2, size=10485760 kB -b the source/base image -f format is qcow2 and the location of the destination image What is so special about this? It's even quicker than creating a template with OpenVZ but this is an actual OS. It saves time a........
  • Slow KVM Virtual Machine Performance Solved - Choose the right architecture with the CPU flag


    I am running a 64-bit host and was running a 32-bit XPguest which was crawling no matter what I was doing with it,in fact it frequently used 100% CPU power while having no real work load. I experienced with this other guests and wondered why KVM was slow compared to say Xen or Virtualbox. This is because you need to use the "-cpu" flag. For a full list of options run: /usr/libexec/qemu-kvm -cpu ? x86 ........
  • VirtualBox Convert Import/Boot .vmdk VMWare Hard Disk/Drive Image Won't Work


    I wanted to Import/Use a .vmdk hard disk image file from VMWare. Generally you can just "point" VirtualBox to it and use it and it will work but I found an exception. One of my Centos 4.4 x64 images wouldn't boot. I had two copies, an older one and the newer one. The older one booted as normal (once I changed the VirtualBox driver to IDE from SATA). The newer one stopped at the "GRUB loading" message no matter what I tried. As far as........
  • Latest Articles

  • How To Install OpenProject on Centos 7 Step-by-Step Guide
  • Ubuntu Debian Linux Cannot Install Wine Solution - wine1.6 : Depends: wine1.6-i386 (= 1:1.6.2-0ubuntu14.2) but it is not installable wine1.4 : Depends: wine1.6 but it is not going to be installed
  • How To Install python 3.4 3.5 and up on Linux with wine - Working Solution
  • using Xvfb on virtual remote ssh server to have X graphical programs work
  • ssh Received disconnect from port 22:2: Too many authentication failures
  • named bind errors - DNSKEY: unable to find a DNSKEY which verifies the DNSKEY RRset and also matches a trusted key for '.'
  • OpenVZ vs LXC DIR mode poor security in LXC
  • httpd: Syntax error on line 221 of /etc/httpd/conf/httpd.conf: Syntax error on line 6 of /etc/httpd/conf.d/php.conf: Cannot load modules/libphp5.so into server: /lib64/libresolv.so.2: symbol __h_errno, version GLIBC_PRIVATE not defined in file libc.s
  • Radeon R3 GPU on Debian Crashing
  • MySQL 5.7 on Debian and Ubuntu - How To Reset Root Password
  • SSH and sshfs timeout settings keepalive
  • Linux How To Add User To Additional Group
  • Howto Set Static IP on boot in initramfs for dropbear or other purposes NFS, Linux, Debian, Ubuntu, CentOS
  • Convert and install to LUKS Encrypted Drive Ubuntu 18.04 19.10 Linux Mint and Debian Based Linux
  • Debian and Netplan
  • CentOS 8 how to restart the network!
  • CentOS 8 how to convert to a bootable mdadm RAID software array
  • ADATA USB Thumb Drive Issues
  • KMODE EXCEPTION NOT HANDLED - QEMU/KVM Won't Boot Windows 2016 or 10 Image or Physical Machine
  • Linux Mint / Ubuntu / Debian Mate Disable Guest Session and Hide Usernames on Lightdm Login screen GUI