# How are the blockSpace thresholds calculated for Element

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#### Applies to

• NetApp SolidFire SF-Series
• NetApp H-Series

They are calculated based on the following equations:

1. Total block capacity - (largest node capacity + 3 % of total block capacity) = Cluster error threshold
2. Cluster error threshold / Total block capacity = % at which the system generates the error message

Block capacity is obtained by API Call `GetClusterCapacity ` under `maxUsedSpace`

You can consult raw capacity per node type on following KB: What is the raw block and metadata capacity for SolidFire and H-Series nodes?

Example on how it is calculated:

For five SF9605 nodes:

• Total block capacity of five SF9605 nodes (5 x 8,640GB) = 43,200 GB
• Largest node capacity = 8,640GB

Three percent of total block capacity (43,200GB x 0.03) = 1,296 GB
Applying these values to the formula, the following results are obtained:

1. Total block capacity - (largest node capacity + 3 % of total block capacity) = Cluster error threshold
2. Cluster error threshold / Total block capacity = % at which the system generates the error message

43,200 - (8,640 + 1,296) = 33,264
33,264 / 43,200 = .77 (or 77 %)

Interpret the results of the above example as follows:

• A `BlockClusterFull` error code will appear when the cluster is 77% (33,264 GB) full.
• The system default for generating a warning severity message is 3% below the calculated error severity. In this example, the system would generate a warning severity when the cluster is 74% full.
• If you want to be notified with a warning severity message before the 74% threshold is reached, you can specify the threshold percentage at which you want to see a warning on `Cluster -> Settings -> Cluster Full Settings` field.
• For example, if you want a warning message at 10% below the error severity (77%), then enter 10 in the 'Raise a warning alert when `_ % `capacity remains before Helix could not recover' field. A warning severity will then be generated when 67% of the cluster is full.