Hi @insurin
One way to start to track down what type of data is causing that 8gb a day is to look at how much data is each index, if the 8gb a day relative to the overall size of data in your Stack is enough to be statistically noticeable.
If you go to Stack Manager -> Index Management -> Data Streams you should be able to see a screen like the one below that gives the size of each index. Could you check that size across two days to see which index/indices are filling up? Or if you have an alternative way to try to triage where that data volume is coming from that would work too. Then we can try to find a way to lower that 8gb per day volume.
