The backup has failed with the following error:
Limit for the maximum number of semaphores reached. You can check and set the limits in /proc/sys/kernel/sem
This is not an OnApp error. It is related to the LVM configuration. For more details, go to https://unix.stackexchange.com/questions/12746/how-do-i-increase-the-number-of-semaphore-arrays-in-linux.