Protection policies

OneFS provides a number of protection policies to choose from when protecting a file or specifying a file pool policy.

The more nodes you have in your cluster, up to 20 nodes, the more efficiently OneFS can store and protect data, and the higher levels of requested protection the operating system can achieve. Depending on the configuration of your cluster and how much data is stored, OneFS might not be able to achieve the level of protection that you request. For example, if you have a three-node cluster that is approaching capacity, and you request +2n protection, OneFS might not be able to deliver the requested protection.

The following table describes the available protection policies in OneFS.

Protection policy Summary
+1n Tolerate the failure of 1 drive or the failure of 1 node
+2d:1n Tolerate the failure of 2 drives or the failure of 1 node
+2n Tolerate the failure of 2 drives or the failure of 2 nodes
+3d:1n Tolerate the failure of 3 drives or the failure of 1 node
+3d:1n1d Tolerate the failure of 3 drives or the failure of 1 node and 1 drive
+3n Tolerate the failure of 3 drives or the failure of 3 nodes
+4d:1n Tolerate the failure of 4 drives or the failure of 1 node
+4d:2n Tolerate the failure of 4 drives or the failure of 2 nodes
+4n Tolerate the failure of 4 drives or the failure of 4 nodes
Mirrors:

2x

3x

4x

5x

6x

7x

8x

Duplicates, or mirrors, data over the specified number of nodes. For example, 2x results in two copies of each data block.
Note: Mirrors can use more data than the other protection policies, but might be an effective way to protect files that are written non-sequentially or to provide faster access to important files.

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