This article applies as of PRTG Data Exporter 1.0

How to calculate disk space

The amount of disk space that PRTG Data Exporter require depends on the amount of exported data.

Example

You have 1,000 sensors with five channels each. Each sensor has a scanning interval of five minutes and the collection period is one month.

Step 1: Calculate the number of scans within the collection period

The number of scans is the collection period divided by the scanning interval. The units of the collection period and the scanning interval must match to calculate the number of scans correctly.

In this example, the scanning interval is in minutes but the collection period is in months. Therefore, we calculate how many minutes are in one collection period, or one month: 43,200 minutes.

Now we can input our numbers into the formula:

Number of Scans = Minutes in collection period ÷ Scanning interval

                               = 43,200 minutes ÷ 5 minutes

                               = 8,640 scans

ℹ️ The number of scans is the number of scans per channel in the sensor.

ℹ️ If your scanning interval is shorter or longer, it might make more sense to use a unit other than minutes in this calculation.

Step 2: Calculate the number of rows in the database

To calculate the number of rows that our data takes up in the data base, we need to multiply the total number of channels by the number of scans per channel. 

In this example, we can calculate the total number of channels by multiplying the number of sensors by the number of channels in each sensor:

Number of channels = Sensor count x Channel count per sensor

                                    = 1,000 sensors x 5 channels each

                                    = 5,000 channels

Next, we calculate the number of rows:

Number of rows = Channel count x Number of scans

                             = 5,000 channels x 8,640 scans per channel

                             = 43,200,000 rows

Step 3: Calculate the necessary disk space

Every row in the ChannelValue table requires around 125 bytes of data. To calculate the disk space, multiply the number of rows that your data occupies by 125 bytes.

Required Disk Space = Number of Rows x 125 bytes

                                    = 43,200,000 rows x 125 bytes

                                    = 5,400,000,000 bytes, or 5.4 GB

Therefore, you need at least 5.4 GB of disk space on the system that runs PRTG Data Exporter in this example.