Category: Virtualization / KVM / VirtualBox / xenserver

it is actually like this, in virt-manager, that chipset and bios can only be changed during first setup “begin installation” it then is fixed and can not be changed in virt-manager

let’s say: in theory – it works in reality – there are (currently) massive sata harddisk driver problems between esxi 6.7 and kvm-qemu’s virtual harddisk admin-user know: esxi is hardware picky (Dell bought VMWare in 2004 so, “officially” only Dell […]

thanks to this excellent script it is now possible to nat-port forward multiple ports from: [internet]<->port:host<->vm thanks & great work all invovled 🙂 here is the script: etc_libvirt_hooks_qemu.txt (and here an older backup of the same) in NAT mode, the […]

hostnamectl; # tested on Static hostname: lenovo Operating System: Debian GNU/Linux 10 (buster) Kernel: Linux 4.19.0-17-amd64 Architecture: x86-64 # with virsh –version 5.0.0 libvirtd –version libvirtd (libvirt) 5.0.0 /usr/bin/kvm –version QEMU emulator version 3.1.0 (Debian 1:3.1+dfsg-8+deb10u8) Copyright (c) 2003-2018 Fabrice […]

tested on host # debian 10 this option is only available in the gui on newer versions of virsh-manager to create a thin provisioned harddisk of capacity of 32GB image via bash-terminal go: qemu-img create -f qcow2 name-of-harddisk-image.qcow2 32G as […]

the error message basically means: the VM’s screen can not be auto-resized because the VBoxGuestAdditions kernel module drivers software was not properly build & installed. the solution: rebuild & reinstall the VBoxGuestAdditions (kernel module) properly: hostnamectl; # tested on guest […]

so RedHat developed the virsh manager, but not qemu itself. https://stackoverflow.com/questions/43704856/what-are-the-differences-between-qemu-and-virtualbox QEMU is a generic and open source machine emulator and virtualizer. When used as a machine emulator, QEMU can run OSes and programs made for one machine (e.g. an […]

hostnamectl; # tested on Static hostname: hpServerG6 Operating System: Debian GNU/Linux 10 (buster) Kernel: Linux 4.19.0-12-amd64 Architecture: x86-64 su – root; apt update; apt install qemu-kvm libvirt-clients libvirt-daemon-system bridge-utils virtinst libvirt-daemon virt-manager usermod -a -G libvirt user; # give user […]

btw: love kvm (used by very large companies) just as virtualbox (oracle) the task: over the years a windows vm is using up massive amounts of precious server harddisk space (snapshots before everyupdate) all the snapshots now add up to […]

update: while this benchmark is still valid, very simple, very cross platform, with a focus on the team cpu (why is there no multi core md5? (putting many many core arm servers at disadvantage) + harddisk (two very important components) […]

i really like virtualbox and i think it has great potential, what i do not like SOOO much is the CIA’s involvement with Oracle. “Larry Ellison Is A Billionaire Today Thanks To The CIA” (src) VirtualBox is mostly GPL 2.0 […]

in addition to select “IDE emulate” in VM Settings one should also restart 1) client 2) server 3) vm  

sometimes one wants to restart a windows vm every x days – to clean up RAM and Co. run task scheduler “Aufgabenplanung” %windir%\system32\taskschd.msc /s File/Datei -> New/Neu -> Basic Task/Einfache Aufgabe select or copy paste: %SystemRoot%\System32\shutdown.exe one has to scroll […]

running esxi inside virtualbox vm is just a test, to play with it, unfortunately one will not be able to start vms on it, because of the lack of nested virtualization. (could/should work nested inside quemu-kvm?) the problem: should have […]

Update: kvm is also a good alternative, but only on linux hosts, so if the user plans to move vms between linux and windows hosts, virtualbox is the way to go. Update: 2020-02: VirtualBox 6.1 is available in repository “Debian […]

# setup log of VirtualBox Graphical User Interface Version 6.0.10 r132072 (Qt5.7.1) # on Debian 9.8 with Cinnamon Desktop # go into software repo user@debian98:~$ cd /software/ # download latest version of software user@debian98:/software$ wget https://download.virtualbox.org/virtualbox/6.0.10/virtualbox-6.0_6.0.10-132072~Debian~stretch_amd64.deb –2019-08-03 14:36:05– https://download.virtualbox.org/virtualbox/6.0.10/virtualbox-6.0_6.0.10-132072~Debian~stretch_amd64.deb Resolving […]

usually host-shared-folder get auto-mounted during boot via vboxsf kernel module. symptoms: # manually mounting the by-host-shared-folder “projects” # as user with uid 1000 and groupid 1000, results in: mount -t vboxsf -o uid=1000,gid=1000 projects /media/sf_projects # also try: mount -t […]

Short stoy: AltGr (HostKey) + C will quit “seamless (no menues) mode” really like the cross-os capabilties of virtualbox (possible to move vms between GNU Linux and Windows servers) and think it has great potential, what is not so great […]

this is a very very basic sequential harddisk write test performed on host and guest. there are multiple ways, how you could improve the performance: Use fixed size disks Allocate RAM and CPUs wisely Install the Guest Additions enable host […]

first of all: i (still) love VirtualBox. The ability to migrate VMs between Windows and Linux servers is really cool, and it is still free to use. NO other Virtualization software can do that! 🙂 and that is exactly my […]

lately on WCG: Avoid CO2 use the Fusion Reactor in the Sky (if the 2 is pronanced German than it even rhymes) as a lot of fossil fuel is (still in 2021!) used to produce electrictiy, it is possible and […]

basically everything that you can do with the super conveniant virtualbox gui you can do from the commandline on a headless server. # set default vm directory # where all vms should reside in # also if you clone a […]

WARNING! WARNING! WARNING! BACKUP BEFORE UPDATING ANYTHING! it is also recommended, to do extensive testing of updates on a 1:1 test-system before updating production! while security is important so is speed/availability/uptime/downtime. upgrades especially of kernel and virtualbox need to be […]

there are a lot of service providers where you can rent a virtual server… for example: hetzner, for 3€ per Month you would get 1x CPU core and 2GB of RAM, instead of VPS they also call it “cloud”, it […]

host: hostnamectl Static hostname: CentOS1.localdomain Operating System: CentOS Linux 7 (Core) CPE OS Name: cpe:/o:centos:centos:7 Kernel: Linux 4.14.12 Architecture: x86-64 vboxmanage -v 5.2.6r120293 1. shutdown the guest VM (Windows 7 64Bit) 2. make sure in the settings you have usb […]

headless server: tested: 2018-10-17 on CentOS Linux 7.5 (Core) wget https://www.virtualbox.org/download/oracle_vbox.asc rpm –import oracle_vbox.asc cd /etc/yum.repos.d/ wget https://download.virtualbox.org/virtualbox/rpm/el/virtualbox.repo yum update yum search virtualbox yum install VirtualBox-5.2.x86_64 # if you want/need usb 3.0 extension package wget https://download.virtualbox.org/virtualbox/5.2.20/Oracle_VM_VirtualBox_Extension_Pack-5.2.20.vbox-extpack VBoxManage extpack install Oracle_VM_VirtualBox_Extension_Pack-5.2.20.vbox-extpack […]

who is who? concepts: docker is written in Google Go by Docker Inc, SanFrancisco because it does not emulate any hardware – it is a linux container / sandbox or jail like Free BSD Jail or Solaris Zones or OpenVZ so […]

update: gaming inside kvm vm on GNU Linux host? YES! but TWO (2x) GPUs / dedicated grafix cards are needed! (or one one onboard gpu and one PCIE dedicated GPU card) “QEMU/KVM VGA PCI Pass-Through of a dedicated AMD Radeon […]

Update: as of 2019-01 and CentOS 7.6 the below setup may fail by now, for those reasons… BUT you CAN compile the latest kernel and all modules yourself (DON’T BE SHOCKED! YOU CAN DO IT! IT’S NOT ROCKET SIENCE!… just […]

this applies to: VirtualBox Version 5.1.8 r111374 (Qt5.3.2) hostnamectl Static hostname: DebianWorkstation Operating System: Debian GNU/Linux 8 (jessie) Kernel: Linux 3.16.0-4-686-pae Architecture: x86 the VMs hangs on startup with this screen: Solution: kill the vm then disable audio device… the […]