Instances launched before Monday Aug 4th 2021 in the QRIScloud availability zone will fail to resize properly. This is due to a change in the way instances are hosted as part of bringing online our new infrastructure. Affected instances will report their CPU model as "AMD EPYC 7501 32-Core Processor" before resizing (however, if you have already resized it should report "AMD EPYC 7642 48-Core Processor" instead). On completing a resize, affected instances will effectively have been rebuilt as the backend driver for storage is different and cannot copy data from the old hypervisor to the new hypervisor through the openstack code. The original root disk is still stored on the old infrastructure and has not been deleted. Please raise a support case to get the root disk copied manually from the old infrastructure to the new or revert to the original location with "openstack server resize revert".
Instances launched after Monday Aug 4th 2021 are not affected and should report "AMD EPYC 7642 48-Core Processor" as their cpu type before the resize. These instances are safe to resize.
To find out the cpu type of your instance, please use lscpu or a similar tool from inside the instance.