when expanding the disk, the disk is recreated

[sergey-ostrovskiy]

Hello

terraform version v1.4.5 provider version v0.7.1

I want to increase the disk, but at the same time the disk is recreated and the data from it is deleted.

Initially I use an empty disk and install the OS through pxe

Change disk size in resource libvirt_volume

what am I doing wrong?

[Magnitus-]

You are not doing anything wrong. The resource is configured to be recreated if the volume size change: https://github.com/dmacvicar/terraform-provider-libvirt/blob/main/libvirt/resource_libvirt_volume.go#L40

You have some options open to you to circumvent this:

• If you have an HA setup (etcd cluster, postgres with patroni, opensearch cluster with all indexes having replica factor greater than 1, etc), you can recreate your vms one by one and let them resynchronize with barely noticeable effects on the system (though if you can restore the new vms from a backup so that it is not too far behind, the synchronization will be less resource intensive). I'd backup the data just in case before doing this though (in theory, HA solutions should support this gracefully, in practice, software can have bugs)
• If you don't have an HA setup, then you will need to:
  • Ensure you have an up to date backup
  • Bring destroy your vm and incur some downtime
  • Re-create the vm and restore from your backup

Alternatively, you can:

• Change your terraform code with the new disk size
• Change the terraform state to resize the vm's disk
• Manually change the disk size
• Go into your vm to make the necessary adjustments to utilize the increased disk size (ie, increase partition size)
• Either way, I'd backup your vm (and the terraform state) before doing this in case something goes wrong. This would be a rather error-prone process. Also, you'll have to shutdown your vm temporarily and incur some downtime anyways.

But the last solution would definitely be working against the grain of what terraform and this provider does.