Recently I am testing kubernetes with 1 master node and 3 worker nodes that built on Openstack(version: Wallaby). It involves lots of testing and therefore I would like to back up the volume to local machine beforehand.
The volume backend is using Ceph. Browsing through the internet and it suggests the conversion of volume to image and download the image to local machine. I can perform the conversion successfully to QCOW2 format for my 20GB volume. However, it failed for my 120GB volume.
I have performed the below checking:
(1) I have checked the glance configuration under /etc/glance/glance-api.conf. The image_size_cap parameter is set to 4TB. I have restarted the glance api service as well.
(2) I checked the ceph backend using ceph df command and ceph has enough capacity.
(3) The glance node has enough storage as well. However, I tried to check the image converting progress under /var/lib/glance/images but the directory is empty even if there are images existed on Openstack.
Have anyone hit the same? And could give me some suggestion..
Thank you so much in advance.
The conversion from volume to image happens on the local disk of the controller. Check
df -hwhile the conversion is running, your/varfilesystem could be filling up if you haven't enough disk space. Check the directory/var/lib/cinder/conversion, this is where the volume is temporarily stored before uploading it back to ceph as an image. It's a good idea to have an own logical volume (if you use LVM) for/var/lib/cinder/conversionto prevent the filesystem from filling up. If you don't have enough local disk space you could just mount a shared filesystem (e.g. cephFS, NFS, etc.) to/var/lib/cinder/conversion.