We are in the process of doing some planned maintenance to our VMware hosts (put one into maintenance mode, patch, move on to the next etc) at our source side and during the this process, have noticed that the storage free at the destination rapidly decreases. I assume this is the journal size increasing on VPGs that have been vMotioned to other hosts. Can anyone please explain this behavior? We nearly ran out of storage on the destination during this task when we though we have plenty of reserve, so need to understand so that we can size our environment correctly.
I have asked internally about this behavior. I will respond as soon as I hear back.
I’ve gotten quite a bit of preliminary feedback from my team so allow me to share:
There seems to be a general consensus and the team cannot think of reasons why Zerto would increase the journal size in this scenario. There may be external factors that can cause this behavior. If you see an increase in throughput and IOPS in the GUI, the cause is likely an environmental one.
We have some customers that have observed the exact behavior you a seeing. Support is currently working with them to see if this a bug / find the root cause of the issue. In the meantime, I suggest you open a support ticket as soon as you can so you can give the team more data to accurately solve the issue.
Lastly, Zerto Analytics long-term reporting might be able to give you some further data. You can view the journal size over time for each individual VPG and see for yourself whether the journals have in fact grown over the time frame.
I hope this gives you something to work with!