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computing:virtmanagerhell [2022/12/04 22:11] – oemb1905 | computing:virtmanagerhell [2023/01/15 17:47] (current) – oemb1905 | ||
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qemu-img convert -p -f raw -O qcow2 guest1.img guest1.qcow2 | qemu-img convert -p -f raw -O qcow2 guest1.img guest1.qcow2 | ||
- | qemu-img convert -p -f qcow2 -O raw gust1.qcow2 guest1.raw | + | qemu-img convert -p -f qcow2 -O raw guest1.qcow2 guest1.raw |
| | ||
If you do end up using this, then you will need to edit the virtual machine' | If you do end up using this, then you will need to edit the virtual machine' | ||
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qemu-img resize disk.qcow2 1000G | qemu-img resize disk.qcow2 1000G | ||
qemu-img resize disk.qcow2 +10G | 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. | ||
+ | |||
+ | fstrim -v / | ||
+ | qemu-img convert -O qcow2 guest.qcow2 guest-trimmed.qcow2 | ||
+ | qemu-img convert -O qcow2 -c guest.qcow2 guest-trimmed.qcow2 | ||
+ | | ||
+ | To test trimming functionality, | ||
+ | |||
+ | dd if=/ | ||
+ | | ||
+ | To create a backup volume inside a guest you create the volume, attach it, and then shell into the guest and format, mount, and create an fstab entry. First, on the hostOS: | ||
+ | | ||
+ | cd / | ||
+ | qemu-img create -f qcow2 vm1-backup.qcow2 32G | ||
+ | virsh attach-disk guestOS.qcow2 \ | ||
+ | --source / | ||
+ | --target vdb \ | ||
+ | --persistent | ||
+ | | ||
+ | Then, on the guestOS: | ||
+ | | ||
+ | mkdir /mnt/backup | ||
+ | mkfs.ext4 /dev/vdb | ||
+ | mount -t auto /dev/vdb /mnt/backup | ||
+ | nano /etc/fstab | ||
+ | /dev/vdb /mnt/backup ext4 defaults, 0 0 | ||
The rest from here on out is my attempt at resizing an .img virtual disk using tools exclusively from virsh / virt-manager. These are highly risky moves and totally not needed for day to day operations. It was more of a mission I was on and based on a tutorial I used nearly 15 years ago when expanding a Windows VM I used for teaching software that was only on that VM. At any rate, I have only succeeded twice doing this, and often get confused looking at the l00ps. Proceed with caution! | The rest from here on out is my attempt at resizing an .img virtual disk using tools exclusively from virsh / virt-manager. These are highly risky moves and totally not needed for day to day operations. It was more of a mission I was on and based on a tutorial I used nearly 15 years ago when expanding a Windows VM I used for teaching software that was only on that VM. At any rate, I have only succeeded twice doing this, and often get confused looking at the l00ps. Proceed with caution! | ||
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kpartx -d debian10.img | kpartx -d debian10.img | ||
- | --- // | + | --- // |