You'll notice that /etc/resolv.conf contains dire warners on most Linux Desktops. # This file is managed by man:systemd-resolved(8). Do not edit. # # This is a dynamic resolv.conf file for connecting local clients to the # internal DNS stub resolver of systemd-resolved. This file lists all # configured search domains. # # Run "resolvectl status" to see details about the uplink DNS servers # currently in use........

1 - Install Vagrant apt install vagrant Make sure you have a supported Virtualization tool like Virtualbox or VMWare, Hyper-V etc.. It automatically detects and uses what you have. Virtualbox has a lot of support here with tons of images. 2 - Init Vagrant We'll init to have a Debian 10 box by default to show how quick and easy it is. vagrant init generic/debian10........

Virtualbox is a very powerful tool, but for some use cases it is less than optimal. Say you are in a work, lab or other environment where you are not alone on the physical network and there could be overlap of IPs, but you need all of your VMs to be contactable from your host, VMs need to communicate with each other, and VMs need internet. NAT Network will give you VM to VM communication and internet, however, it is buggy and unstable. It also doesn't allow host to VM co........

If you find your NAT Network is not working properly, the first thing you may want to do is list the networks, check their status and make sure the Network is actually started and configured as you expect (eg. is DHCP on and enabled?). This is a long known, unresolved bug that seems to affect Version 6 randomly and disportionately on especially Mint 20/Ubuntu 18. https://www.virtualbox.org/ticket/1474........

Bonding is an excellent way to get both increased redundancy and throughput. It is similar to the "Network Teaming" feature in Windows. There are a few different modes but we will use mode 6, I think it's the best of both worlds, as it is not just a failover, but it provides round robin, so you will get redundancy and load balancing. So if you have a 1G single port, you will have a combined throughput of 4G at this point. Just bear in mind that the true thr........

There is a random bug that sometimes occurs with Vbox NAT mode DNS, although it has never happened in the past and Vbox was working fine until recently. The symptom is that you can see it does get an IP+ DNS from the Vbox NAT DHCP. Below we use resolvectl dns and verify the DNS server is set to 10.0.2.3 which is the DNS from Vbox NAT. We can ping it but it does not respond to any DNS requests when we use dig @10.0.2.3 realtechtalk.com........

In newer of versions of Virtualbox, especially above 6.0 (eg. 6.1 like the example below), a lot of times the "Enable Nested VT-x/AMD-V". If you are having this issue, you will see the option is grayed out. It doesn't mean that your computer does not support virtualization, although it is possible it is disabled in the BIOS. You can verify........

NAT Network, the VMs can communicate but your host cannot access them by default. NAT VMs have internet but cannot communicate with each other. Bridged is simple and allows full LAN access as if you had a physical machine plugged in but is often bad for testing, work or corporate environments and is not very portable when it comes to moving your VMs to other locations and networks. Here is how you can use NAT Ne........

The Linux Mint team has disabled it by setting an apt preference, you can edit or just remove the file: sudo apt install snapd Reading package lists... Done Building dependency tree Reading state information... Done Package snapd is not available, but is referred to by another package. This may mean that the package is missing, has been obsoleted, or is only available from another source........

Just install these packages and restart the VM: 1.) Enable guest-utils on the host side: sudo apt install virtualbox-guest-utils virtualbox-guest-x11 2.) Enable guest editions on the VMside This must be done for each VM that you want to have the guest additons for accelerated GPU performance and for drag and drop/clipboard sharing First insert the Guest Addtions CD image........

This seems to be an ongoing issue that is still reproducable in the latest Ubuntu Vbox 6.x. The default NAT Network range is usually 10.0.2.0/24. If you change this range it does not seem to work properly. Say we change the range to 10.50.1.0/24 If you get a new lease you will find that you get an IP from the old range but the default gateway is from the new range. ........

Cannot register the hard disk '/some/path/windows-marking.vdi' {f54def00-2252-43f5-9178-0998636cad61} because a hard disk '/other-path/windows-marking.vdi' with UUID {f54def00-2252-43f5-9178-0998636cad61} already exists. Result Code: NS_ERROR_INVALID_ARG (0x80070057) Component: VirtualBoxWrap Interface: IVirtualBox {0169423f-46b4-cde9-91af-1e9d5b6cd945} Callee RC: VBOX_E_OBJECT_NOT_FOUND (0x80BB0001)........

If you've just installed VBox and it is not starting or working, the most common problem is usually that you don't have your kernel source installed, which means there is no kernel driver for vbox so it can't work. You may get an error that says "Kernel driver not installed" in your Virtualbox. So the first thing you should do is install your kernel source by running this: sudo apt-get install linux-headers-`uname -r`........

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........

#to show all VBoxManage list vms #show ONLY running vms VBoxManage list runningvms VBoxManage storageattach test --storagectl "SATA" --port 0 --device 0 --type hdd --medium iscsi --server 192.168.1.91 --target "iqn.2018-12.local.abcrandom.target:sdb" --initiator "iqn.1982-01.ca.bla.tld:abc123" --t........

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........

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........

Intel VT-X is enabled in Virtualbox but it doesn't seem to pass through the needed vmx extension despite the following variables on the host confirming it is enabled: cat /sys/module/kvm_intel/parameters/nested Y cat /sys/module/kvm_intel/parameters/ept Y OVF Tool: Disk progress: 99% OVF Tool: Transfer Completed OVF Tool: Powering on VM: Embedded-vCenter-Server-Appliance- OVF Tool: Task p........

This is not the normal "black screen"issue and I was shocked to eventually find out why. The normal advice of reconfiguring Xorg didn't work. Even booting into "Recovery Mode" did not help. Here is the short end of the stick that fixed it: sudo apt-get install mdm mate-desktop-environment Yes you got it right, mdm and the mate-desktop-environment / gnome were somehow uninstalled. This must be whe........

Just type the command: localboot By default it will boot the first local drive "0". Ibelieve you can specify a different number to boot a different device. eg. localboot 3 (will boot the 4th BIOS device)'........

VBoxManage modifyhd "my.vdi" --resize 60000 Note the above will resize my.vdi to 60,000MB........

In Firefox I cannot connect to any website, proxy is disabled and outside network access is confirmed, no system or manual proxy was set on this Linux Mint/Ubuntu system. Normally this can be caused by proxy or DNS problems and the weird thing is that traceroute and ping to other IPs worked fine but even connecting to sites by IP was not working. The connection was reset The connection to the server was reset while the page was loading.........

Cannot register the hard disk '/media/Debian8.vdi' {d01efabc-aacf-4614-b29c} because a hard disk '/home/VirtualBox VMs/Debian/Debian8.vdi' with UUID {d01efabc-aacf-4614-b29} already exists. This is what happens if you move the VDI to another location. The easiest way is to delete/remove the machine from VBOX and then reimport it from the new location.........

In plain English this happens after you upgrade VBOX and it rebuilds kernel modules based on a newer kernel than you are running (eg. you upgraded your kernel but haven't booted into it). It is too bad there is not a standard work around that would allow it to realize this and keep old kernel modules and use them if it detects your current kernel is older than the most recently build modules. =============== RTR3InitEx failed with rc=-1912 (rc=-1912) The........

The solution was to reinstall the vbox dkms package and do a manual modprobe of the modules it makes. I never sorted out the unable to start due to the USB issue, I did have the guest additions installed but the only way to boot was to change the pointing device from USB to PS2 and then to disable the USB controller (if your pointing device is set as USB, disabling USB will not work because it will re-enable by default when it sees your pointing device is USB, this is w........

It is a permissions issue that is hard to fix. All but one USB device is greyed out. I am already a member of "vboxusers" I have already enabled and disabled USB support for the guest. I have already reinstalled the latest VBOx guest editions If running as root it all works fine Changing........

The solution is to run '/etc/init.d/vboxdrv setup' and sometimes happens when upgrading VBox and the kernel modules don't get upgraded with it. Sometimes the above doesn't work until you reboot because sometimes other unknown processes (even the file manager possibly) may be locking the old module from being unloaded. Failed to open a session for the virtual machine XP. The virtual machine 'XP' has terminated unexpectedly during startup with exit code 1.........

Failed to load VMMR0.r0 (VERR_SUPLIB_OWNER_NOT_ROOT) In most cases the error above is useful, it generally means /usr or /usb/lib or /usr/lib/virtualbox is not owned by root and this is the cause of the error. Solution sudo chown root.root /usr/lib........

VBox/Virtualbox solution to NS_ERROR_CALL_FAILED error This is likely because you have 2D/3D acceleration enabled and your card doesn't support it. Eg. you switched video card drivers or video cards that did support it. The funny thing is that you CANNOT disable those options as they are "greyed" out in the VBox client GUI. The config file has to be manually changed and fixed with these options "accelerate3D="false" accelera........

I haven't updated VBOX in ages but have never seen this issue and it has my CPU running at 100C. Manually/forcefully killing the process does not work with "kill -kill 3892". I've closed the VBOXManager and everything else related to it. This did seem to happen around the time I ran VBoxManage clonehd and it failed, the terminal issue locked up and also never wrote a byte of anything. I forced killed the VBoxManage and tried to remove &........

This is useful for developing a lot of applications, I'm putting it here to keep it handy for myself and hopefully others: Choose CountryCanadaJapanUnited StatesUnited KingdomAfghanistan........

Failed to open a session for the virtual machine XP. Failed to launch Remote Desktop Extension server (Unknown Status 0x80004005). Disabled remote display: Failed to load VMMR0.r0 (VERR_SUPLIB_OWNER_NOT_ROOT). solution chown root.root /usr/lib/........

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 ........

VBoxManage modifyhd XP.vdi --resize 15000 VBoxManage modifyhd XP.vdi --resize 15000 0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100% That resizes the virtual hard drive image "XP.vdi" to 15000MB instantly. I doubt this is safe to do while the VM is running and I'm not sure if it would attempt it still but turn the VM off first to be safe. I also notice in the VBOX GUI that it still shows the orig........

I've encountered this problem before and I believe it may affect other drivers (I could test but I don't have time). This was happening on my custom Linux system with the pcnet32 driver. pcnet32: eth0: transmit timed out, status 97fb, resetting (and some other kernel module tracing in dmesg) Basically it means the card is connected (it shows connected in full duplex etc.. and recognized if the cable is disconnected too) but no packets can be sent or received........

VBoxManage modifyvdi /path/to/your.vdi compact I believe this should be done only when your VM is powered off, but I decided to try it with the system powered on. i wouldn't recommend it because it's dangerous even if it does work but this is a test system. For anything important/production I would always take a backup first and make sure the system is powered off. VBoxManage modifyvdi XP-clone.vdi compact 0%...10%...20%...30%...40%...5........

You can't just do a straight copy of the VDI image of your virtual machine because there is a unique UUID, wellI believe you can and then you can create a new UUID manually (at least you could with VMWARE) but to keep it clean just use this method: VBoxManage clonevdi /path/to/your.vdi outputname.vdi 0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100% That's all there is to it, just wait for it copy and you can th........

Virtualbox hang problem A VM just froze and wouldn't close so I had to force it, but the VBox GUI thinks it's running even when I close it. I manually killed the related process by doing ps aux|grep VirtualBox and found the PID 6191 I killed it with "kill -kill 6191" but it remains open and as "defunct" so I can't restart it because the GUI freezes when I click on it because it thinks it is running still........

I was afraid to remove the virtualbox 3.2 package in Ubuntu because I didn't know if it might remove the .virtualbox folder which contains all of my VM data. I have a backup soI did remove the package and found everything was intact, so I installed and upgrade to VBOX 4.0 which seems to be a huge improvement, especially in UI performance.........

Failed to open a session for the virtual machine XP. AMD-V is being used by another hypervisor. (VERR_SVM_IN_USE). VirtualBox can't enable the AMD-V extension. Please disable the KVM kernel extension, recompile your kernel and reboot (VERR_SVM_IN_USE) Solution - Unload KVM module (you can't use two hardware virtualization suites at once) sudo rmmod kvm_amd kvm........

Centos 5 Postfix and SPAMASSASSIN Tutorial yum install spamassassin chkconfig spamassassin on vi /etc/mail/spamassassin/local.cf ############## #required_hits 5 #report_safe 0 #rewrite_header Subject [SPAM] #5 is the least restrictive (means only the most obvious SPAM is caught. 0 is obviously the most restrictive/sensitive and would have lots of false positives require........

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........

The solution is simple but it's a wonder why VBOX doesn't address it directly? Perhaps newer versions will but you have to add your user to the "vboxusers" group and then login and logout and you'll see the devices you wanted but couldn't access are now available. The weird thing is that the grayed out issue doesn't happen with all devcies but one notable thing is the Apple iPhone especially in DFU or Recovery Mode which is an big issue for some people.........

Virtualbox Error I tried to copy a .vdi of one container to use in another one, basically to clone instead of having to install the OS again. Failed to start the virtual machine Centos 5.5 Mirror. Medium '/home/testuser/.VirtualBox/HardDisks/Centos 5.5 Mirror.vdi' is not accessible. UUID {a1a9fad7-0402-4867-b8f3-39fb49454bc5} of the medium '/home/testuser/.VirtualBox/HardDisks/Centos 5.5 Mirror.vdi' does not match the value {4945a0e8-0ed5-4736-9088-bcaf........

wget http://download.virtualbox.org/virtualbox/3.2.8/VirtualBox-3.2-3.2.8_64453_rhel5-1.i386.rpm rpm -i http://download.virtualbox.org/virtualbox/3.2.8/VirtualBox-3.2-3.2.8_64453_rhel5-1.i386.rpm error: Failed dependencies: libGLU.so.1 is needed by VirtualBox-3.2-3.2.8_64453_rhel5-1.i386 libSDL-1.2.so.0 is needed by VirtualBox-3.2-3.2.8_64453_rhel5-1.i386 libXmu.so.6 is needed b........

NET: Registered protocol family 2 The above is the last thing that I ever saw, I tried pci=routeirq etc.. and it wouldn't work. The solution is to enable IOAPIC in the VBOX Settings Just enable "IOAPIC" in the settings for your Centos Guest and you'll find the kernel boots just fine. I wonder if a physical system might stall in this same way if the BIOS has IOAPIC disabled which many people do as a troubleshooting method. ........

I shared a directory on my hostnode/local system (running Ubuntu 10.04) with my Guest system running Windows XP. I have no idea why it's not mentioned or documented in an obvious way, but in the Windows client you just access it with "\Vboxsvr" Once you access that share you'll have access to all of the VBOX shares on your local host. I think it should indicate it somewhere when you enable the sharing. Yes, I'm sure it's buried so........

GRUB Boot FreeBSD[code:1:a7050277b7]title FreeBSD 6.0 root (hd0,2,a) kernel /boot/loader[/code:1:a7050277b7] Just insert the above code into GRUB's [b:a7050277b7]menu.lst[/b:a7050277b7] and make sure you set the root path correctly. [quote:a7050277b7]Let's quickly explain what the root (hd0,2,a) means: *hd0 stands for the primary master drive *2 stands for partition 3 *a stands for the........

This is unfortunate and frustrating as many sites use it, a lot of people are frustrated that TinyMCE does not work on the iPhone Safari browser. Apparently the developer of TinyMCE's answer is "talk to Apple about it" It's really frustrating although, I wonder if any other mobile phones are able to use TinyMCE or not, whatever the case is it would be nice to find a solution to use TinyMCE on the........

genisoimage: Directories too deep for 'Backup/My Documents/My Music/iTunes/Album Artwork/Local/5928CE9C1AFAC465/07/15' (7) max is 6. Some people said choosing the --iso-level-4 option will help. I just opted to add the "-D" switch and everything was fine.........