Terrible network speed with centos 7 cloud image

ThunderVM

New Member
Jan 13, 2023
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thundervm.com
Hello

I've ran into a quite strange issue with my centos 7 cloud image templates.

Before we proceed:
  • I manually installed a centos 7 vm (from the minimal iso) and it doesn't have any issues
  • I deployed 10 other different distros, including centos stream 9, and all of them don't have any issues
  • I downloaded the iso a month ago, i downloaded the most recent one, thinking it would solve the problem but the issue is still present.

When i setup centos 7 with cloud-init for unknown reasons the network performance is terrible: 3Mb/s in download and upload.
With every other VM (including the manually installed centos 7 vm) the speed reaches 75Mb/s in download and upload.

This is how i create the templates

Code:
SNIPPET=vendor-centos7.yml
IMG_NAME=centos7.img

# download snippet
wget ####### -O /var/lib/vz/snippets/$SNIPPET

# download the image
wget https://cloud.centos.org/centos/7/images/CentOS-7-x86_64-GenericCloud.qcow2 -O /var/lib/vz/template/iso/$IMG_NAME

# create a new VM with VirtIO SCSI controller
qm create 104 --memory 1024 --net0 virtio,bridge=vmbr0 --scsihw virtio-scsi-pci

# import the downloaded disk to the vmdata storage, attaching it as a SCSI drive
qm set 104 --scsi0 local-zfs:0,import-from=/var/lib/vz/template/iso/$IMG_NAME

qm set 104 --ide2 local-zfs:cloudinit
qm set 104 --boot order=scsi0
qm set 104 --serial0 socket --vga serial0
qm set 104 --cicustom "vendor=local:snippets/$SNIPPET"
qm set 104 --agent 1
qm template 104

The custom snippet installs and configures qemu-guest-agent.

Has anyone ever ran into a similar issue?