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computing:virtmanagerhell [2022/08/08 06:41] – oemb1905 | computing:virtmanagerhell [2023/01/02 14:18] – oemb1905 | ||
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- | Alright, I am completely re-writing this as the old notes were just out of date and incomplete. | + | To make a VM from the command line, do the following. Note that this recipe assumes you have already created your virtual switch, br0. It also presumes you have already created your virtual disk, and if you have not, simply run '' |
- | sudo nano /etc/network/interfaces | + | sudo virt-install --name=new.img \ |
+ | --os-type=Linux \ | ||
+ | --os-variant=debian10 \ | ||
+ | --vcpu=1 \ | ||
+ | --ram=2048 \ | ||
+ | --disk path=/mnt/vms/students/ | ||
+ | --graphics spice \ | ||
+ | --location=/ | ||
+ | --network bridge:br0 | ||
- | That file should look like this (adjust | + | To clone an existing image, do the following: |
+ | |||
+ | virt-clone \ | ||
+ | --original=clean \ | ||
+ | --name=sequoia \ | ||
+ | --file=/ | ||
+ | |||
+ | If you have a legacy image that needs to be larger, then install a few tools and the proceed to expand the virtual hard disk as follows: | ||
+ | |||
+ | apt install qemu-img kpartx | ||
+ | qemu-img resize debian10.img +50G | ||
| | ||
- | #eth0 (alt name ent8s0g) physical host base-connection | + | After expanding the virtual hard disk, open gparted in X passthrough / command line and expand the existing partition into as much of the the new space as you prefer. And to rename a VM (domain), do the following: |
- | | + | |
- | | + | |
- | address 8.25.76.160 | + | |
- | netmask 255.255.255.0 | + | |
- | gateway 8.25.76.1 | + | To delete a domain, virt-manager uses the undefine command. To remove the accompanying storage with it, parse the command as follows: |
- | nameserver 8.8.8.8 | + | |
- | | + | |
- | | + | |
- | iface enp8s0g1 inet manual | + | |
- | auto br0 | + | |
- | iface br0 inet static | + | |
- | address 8.25.76.159 | + | |
- | netmask 255.255.255.0 | + | |
- | gateway 8.25.76.1 | + | |
- | bridge_ports enp8s0g1 | + | |
- | nameserver 8.8.8.8 | + | |
- | Once that's done, run '' | + | virsh undefine guest1 --remove-all-storage |
+ | |||
+ | If you need to force stop a machine, virt-manager uses the destroy command, as follows: | ||
- | | + | |
+ | |||
+ | I prefer the raw format (.img) but if I change my mind later, perhaps because I want snapshots, then I can easily shutdown the machine and convert the image as follows. If I change my mind, I can also go in reverse back to raw. | ||
+ | |||
+ | qemu-img convert -p -f raw -O qcow2 guest1.img guest1.qcow2 | ||
+ | qemu-img convert -p -f qcow2 -O raw guest1.qcow2 guest1.raw | ||
| | ||
- | Reboot the host and ping 8.8.8.8 and google.com to ensure | + | If you do end up using this, then you will need to edit the virtual |
- | | + | |
+ | <driver name=' | ||
+ | <source file='/mnt/vms/ | ||
+ | |||
+ | Another essential tool is the ability to create snapshots and, when necessary, revert to them. Here are the commands to create snapshot1 and then later revert to that specific snapshot. | ||
- | This file should look like this (adjust to your use-case - and again, this is **inside | + | virsh snapshot-create-as guest1 snapshot1 --description "first snapshot 11-13-22" |
+ | virsh snapshot-revert guest1 snapshot1 | ||
+ | |||
+ | If you don't care about naming | ||
- | | + | |
- | | + | |
- | | + | To create an external snapshot, append the following arguments: |
- | netmask 255.255.255.0 | + | |
- | gateway 8.25.76.1 | + | |
- | nameservers 8.8.8.8 | + | |
- | The VM interface is listed inside the guest/ | + | virsh snapshot-create-as guest1 snapshot1 |
+ | |||
+ | If you want to revert | ||
- | | + | |
- | ip a | + | |
- | sudo apt install resolvconf | + | |
- | sudo nano / | + | |
| | ||
- | Enter the name server as follows: | + | If you need to delete a particular snapshot, or delete all children of a snapshot, execute: |
| | ||
- | | + | |
+ | virsh snapshot-delete guest1 --current --children-only | ||
- | At this point, I would probably reboot and then from within | + | |
+ | To list all snapshots for a particular guestOS, execute this: | ||
+ | |||
+ | virsh snapshot-list guest1 | ||
+ | |||
+ | To get information about the snapshot, these commands help: | ||
+ | |||
+ | virsh snapshot-info guest1 snapshot | ||
+ | virsh snapshot-dumpxml guest1 snapshot1 | ||
+ | |||
+ | If you need to make a live backup, do the following (Note: make sure that '' | ||
+ | |||
+ | |||
+ | virsh domfsfreeze guest1.qcow2 | ||
+ | qemu-img create -f qcow2 -b guest1.qcow2 snapshot.qcow2 | ||
+ | virsh domfsthaw guest1.qcow2 | ||
+ | |||
+ | |||
+ | At times you may need to resize or gather information about a particular virtual disk. If they are in the qcow2 format, gather information as follows: | ||
+ | |||
+ | qemu-img info disk.qcow2 | ||
+ | |||
+ | To regain space that is being used needlessly, you can sparsify the qcow2 disk. Note that you must install | ||
+ | |||
+ | virt-sparsify --in-place disk.qcow2 | ||
+ | |||
+ | Most importantly, there' | ||
+ | |||
+ | cp -ar --sparse=always disk.qcow2 disk.bk.qcow2 | ||
+ | qemu-img resize disk.qcow2 1000G | ||
+ | qemu-img resize disk.qcow2 +10G | ||
+ | |||
+ | Okay, so another big issue with qcow2 images is them growing over time from writes/ | ||
+ | |||
+ | sudo systemctl enable fstrim.timer | ||
+ | sudo systemctl start fstrim.timer | ||
+ | |||
+ | You can also manually run fstrim and then power down the qcow2 image and convert it. You may optionally use compression to save more space, but it takes very long. | ||
- | -- Below, are notes from when I shrunk an .img file / expanded an .img file (cannot remember lol) -- | + | fstrim |
+ | qemu-img convert -O qcow2 guest.qcow2 guest-trimmed.qcow2 | ||
+ | qemu-img convert | ||
- | Resize | + | The rest from here on out is my attempt at resizing |
| | ||
sudo apt install libguestfs-tools | sudo apt install libguestfs-tools | ||
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kpartx -d debian10.img | kpartx -d debian10.img | ||
- | | ||
- | After messing around with this, and succeeding 1 time in resizing the drive this way, I decided that just issuing '' | ||
- | --- // | + | --- // |