Generally we use kpslice and kernelcare rebootless kernel updates. However, a recent vulnerability with in openvz has been patched in a new kernel, and updates are not yet available through ksplice and kernelcare.
Some servers will be manually upgraded, which requires a reboot. This can take up to 15 minutes. Generally speaking, the ram data is saved to disk and the vps resumes on start up and appear to not have rebooted.
Some servers will be manually upgraded, which requires a reboot. This can take up to 15 minutes. Generally speaking, the ram data is saved to disk and the vps resumes on start up and appear to not have rebooted.