Fault sets

The fault sets are a way to instruct StorPool to use the drives in a group of nodes for only one replica of the data if they are expected to fail simultaneously. Some examples would be:

  • Multinode chassis.

  • Multiple nodes in the same rack backed by the same power supply.

  • Nodes connected to the same set of switches.

Command parameters

You can perform fault set operations on the command line using the storpool faultSet command:

  • When there is no fault set name specified you can use only the list parameter.

  • When there is a fault set name specified you can use the addServer, delete, rename, and rmServer parameters.

Adding a fault set

To define a fault set only a name and some set of server nodes are needed:

# storpool faultSet chassis_1 addServer 11 addServer 12
OK

You can use this command both for creating a new fault set and for adding servers to an existing fault set. For details on how to get IDs of servers using the storpool server command, see Server.

Attention

A new fault set definition has effect only on newly created volumes. To change the configuration on already created volumes a rebalance operation would be required. See Balancer for more details on rebalancing a cluster after defining fault sets.

Listing fault sets

To list defined fault sets:

# storpool faultSet list
-------------------------------------------------------------------
| name                 |                                  servers |
-------------------------------------------------------------------
| chassis_1            |                                    11 12 |
-------------------------------------------------------------------

Renaming a fault set

To rename a fault set you should provide its current name, the rename parameter, and the new name:

# storpool faultSet chassis_1 rename ch_1
OK

Removing a server from a fault set

To remove a server from a fault set you should provide the name of the fault set, the rmServer parameter, and the ID of the server to be removed:

# storpool faultSet chassis_1 rmServer 12

Removing a fault set

To remove a fault set you should provide its name, the delete parameter, and the name again:

# storpool faultSet chassis_1 delete chassis_1