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Bug
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Resolution: Unresolved
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Major
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CNV v4.12.9, CNV v4.15.0
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None
High
Description of problem:
For Portworx filesystem volumes, the overhead appears to be higher than the default 5.5% overhead in CDI. Portworx is using ext4 with default reserved blocks of 5%. So the total overhead looks to be around 7.5%. Since the cluster was having default overhead, the boot source images was only extended to 5.5%.
# oc get pvc rhel9-6c486c3e5f8c -n openshift-virtualization-os-images -o yaml |yq '.spec.resources' requests: storage: "34087042032"
When a new VM was created from this template image (both with csi-clone and host assisted clone), the available size was always less than that of the virtual image size of the disk:
Total Available = 29511680 + 1511424 = 31023104 Ki = 29.58 Gi sh-5.1$ df /var/run/kubevirt-private/vmi-disks/rootdisk/disk.img Filesystem 1K-blocks Used Available Use% Mounted on 172.30.29.72:/var/lib/osd/pxns/1064291030995076819 32716800 1511424 29511680 5% /run/kubevirt-private/vmi-disks/rootdisk
sh-5.1$ qemu-img info /var/run/kubevirt-private/vmi-disks/rootdisk/disk.img image: /var/run/kubevirt-private/vmi-disks/rootdisk/disk.img file format: raw virtual size: 30 GiB (32212254720 bytes) disk size: 1.47 GiB Child node '/file': filename: /var/run/kubevirt-private/vmi-disks/rootdisk/disk.img protocol type: file file length: 30 GiB (32212254720 bytes) <== disk size: 1.47 GiB
If I fill the filesystem from the VM, the VM goes into paused state when it don't have enough space to allocate in the backing filesystem.
sh-5.1$ du /var/run/kubevirt-private/vmi-disks/rootdisk/disk.img 31022448 /var/run/kubevirt-private/vmi-disks/rootdisk/disk.img sh-5.1$ virsh -r list Authorization not available. Check if polkit service is running or see debug message for more information. Id Name State --------------------------------------------------- 1 nijin-cnv_rhel9-lime-chimpanzee-65 paused
Version-Release number of selected component (if applicable):
OpenShift Virtualization 4.15.0
How reproducible:
100%
Steps to Reproduce:
1. Use Portworx filesystem volume as default storage class and populate the boot images of the default templates on this storage class. 2. Create a VM from any of the default template and check the available space from the virt-launcher pod. It will be less than the virtual image size of the image.
Actual results:
Available space is less than virtual image size while creating VMs from templates on Portworx filesystem volumes. When the image grows, the VM may end up in paused state when the backing filesystem don't have enough space.
Expected results:
Validate and provide error message if the target filesystem available space is less than virtual size of the image so that user can increase the overhead.
Additional info:
- relates to
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- Closed
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