In Edge Manager → Diagnostics the available disk space and the total disk space of TrendMiner can be checked. The disk space shown there shows the space on the /mnt/data volume (the volume on which the TrendMiner appliance is installed and on which TrendMiner stores its data).
Next to the /mnt/data volume there is also the root volume, on which the OS and system services are running. Both the root volume and the /mnt/data volume can run out of disk space which in both cases will result in service interruption.
The root volume total disk space and usage is not shown in Edge Manager since TrendMiner does not actively use this volume. Disk space issues should not occur on this volume if the system requirements are met.
The /mnt/data volume is used by the TrendMiner application for storing data. This data mainly consists of:
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Info stored in the database, e.g. saved work from users.
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Index data
Logically, the more usage of TrendMiner and the more tags are being indexed, the more disk space will be required. The minimal disk space requirements listed in our installation guide are in general sufficient to start with TrendMiner but when usage increases it will be required to add more disk space.
How much disk space is needed is very dependent on the exact usage, type of tags, specific configuration but since the tag index data is taking up most of the disk space the following upper limit can be used to calculate the required disk space:
| Index resolution | Disk space required | Examples |
|---|---|---|
| 60 seconds | Worst case: 17MB/tag/year | 1k indexed tags with 3 years of index data = 51GB |
| Average case: 1MB/tag/year | 1k indexed tags with 3 years of index data = 3GB 10k indexed tags with 5 years of index data = 50GB 100k indexed tags with 2 years of index data = 200GB | |
| 5 seconds | Worst case: 204MB/tag/year | 1k indexed tags with 3 years of index data = 612GB |
| Average case: 12MB/tag/year | 1k indexed tags with 3 years of index data = 36GB 10k indexed tags with 5 years of index data = 600GB 100k indexed tags with 2 years of index data = 2.4TB |
This worst case calculation assumes tags have a lot of data and the maximum number of points (based on the configured index resolution) are stored in the index.
In practise however most tags will not use this theoretical maximum amount of disk space.
It is also important to note that disks can be extended at any time but it is not supported to reduce the disk space of a TrendMiner installation.
How much disk space do you use and how many indexed tags do you have?