Transaction storage filesystem sizing

[dcinciripini]

Hi everybody,
Let me explain our situation:
We had a problem with sizing the filesystem dedicated to transaction storage on a 150 HU (small size) environment that we manage. We created a cluster of 3 Dynatrace servers each with a dimensioning of 400 gb for that filesystem therefore ~1.2 TB in total.
The documentation, in this link and in the image below

speaks of 300 gb for 10 days of retention, therefore, if I have not misunderstood, ~1 TB for 35 days.
On the countrary the filesystem filled up and data retention has been truncated to ~23 days, as shown in the image below

My questions are:
- How much more space do you think I need to add? Is it enough to make a ratio 23:35=400:x?
- What was your strategy for sizing the file system dedicated to transaction storage? 

Thanks in advance,
Davide

[Radoslaw_Szulgo · Accepted solution]

We can't provide you with specific and accurate numbers in the documentation. The actual transaction data storage size depends on how many transactions are created within a set data retention time. In one environment, there might be just one distributed trace per minute, and in the other: hundred distributed traces. 

Your assumption on sizing the storage is correct, assuming all daily transactions are equal on average. For example, if you have twice as many calls at the end of the month, you might need more storage. 

The recommendation is to size the storage step-by-step and observe the retention adjustments and metrics until it becomes stable.

[dcinciripini]

Thank you Radoslaw,
your answer was very useful