We have released a new update for the OnApp Cloud v3.0.8 which includes new kernel version for Xen 4 hypervisors (kernel-3.4.53-8.el6.centos.alt.x86_64).
This upgrade only applies to Xen 4 hypervisors. New 3.0.8 OnApp Cloud installation package already comes with the updated kernel.
Note: You only need to upgrade your hypervisors if you experience stability issues with CentOS6/Xen.
The upgrade instructions can be found at: https://onappdev.atlassian.net/wiki/display/GetStarted/Hypervisor+Kernel+Upgrade+for+the+3.0.8+Version
If you continue to experience issues following this update please refer to the following article: