Intro

Since I’m using several servers included I want my guests to be small as possible to transfer those guests to other systems and also to make the back-up experience better and saving space in the end.

I figured this out that I could images smaller when I was following Red Hat Certified System Administrator exam | EX200 book in my free time.

As you can see my images are pretty big, these are stored on a SAMSUNG 1TB SSD and it already taking more than 50% of the storage. I want to make them as small as possible.

33423545 -rw-------.  1 qemu      qemu      257G Jan  1 15:44 ALMA_SERVER.qcow2
33425559 -rw-------.  1 root      root      257G Jan  1 15:36 UBUNTU_SERVER.qcow2

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Qemu-img

Requirements

RHEL/Fedora/Rocky/Alma:

	yum install qemu-utils

Debian/Ubuntu:

	apt-get install qemu-utils

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Qemu-img is a tool to convert your virtual machine images to another format (e.g. VMDK, RAW and VHDX and more.)

As you can see my images are pretty big

```bash
33423545 -rw-------.  1 qemu      qemu      257G Jan  1 15:44 ALMA_SERVER.qcow2
33425559 -rw-------.  1 root      root      257G Jan  1 15:36 UBUNTU_SERVER.qcow2

And with the command:

qemu-img convert -f qcow2 -O qcow2 /var/lib/libvirt/images/$IMAGENAME.qcow2 /var/lib/libvirt/images/$IMAGENAME2.qcow2

I could make them significantly smaller:

33423532 -rw-r--r--.  1 root      root      1.8G Jan  1 15:46 ALMA_SERVER.qcow2
33423545 -rw-------.  1 root      root      257G Jan  1 15:46 ALMA_SERVER_OLD.qcow2
33423544 -rw-r--r--.  1 root      root      3.9G Jan  1 15:47 UBUNTU_SERVER.qcow2
33425559 -rw-------.  1 root      root      257G Jan  1 15:36 UBUNTU_SERVER_OLD.qcow2

Less space is being used and I can still use up to 256GB in my virtual machines. If I need more, I can add more space, since I use LVM.

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Read about LVM

What can LVM do that standard partition can’t?

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