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system node external-cache modify

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Modify external cache settings.

Availability: This command is available to cluster administrators at the admin privilege level.

Description

The system node external-cache modify command can be used to modify the following attributes of external-cache for a node:

  • is-enabled

  • is-rewarm-enabled

  • is-mbuf-inserts-enabled

  • pcs-size

  • is-hya-enabled

Parameters

-node {<nodename>|local} - Node

This specifies the node on which the modifications need to be made.

[-is-enabled {true|false}] - Is Enabled?

Enables external-cache module (Flash Cache Family) on the storage system. Valid values for this option are true and false. If external-cache hardware is present, then this option will enable external-cache functionality in WAFL. If no hardware is present, this option will enable external-cache pcs (Predictive Cache Statistics). The default value for this option is false.

[-is-rewarm-enabled {true|false}] - Is Rewarm On?

Specifies whether an external-cache module should attempt to preserve data across reboots. Valid values for this option are true and false. This option applies only to cache hardware with persistent media. It does not apply to Predictive Cache Statistics (PCS). Enabling this option will marginally increase the duration of system boot and shutdown, but it will reduce or eliminate the time required for cache warming. The default value for this option is determined by the cache hardware type. The option is disabled by default.

[-is-mbuf-inserts-enabled {true|false}] - Is Mbuf Inserts On?

Specifies whether the external-cache module allows insert of mbuf data as part of a network write. In rare cases, inserting mbuf data may cause excessive CPU usage. We provide this workaround to disable the behavior, if necessary. Do not change the value of this option unless directed to do so by technical support. The data from the mbuf network writes can still be stored in the external cache, but only after a subsequent disk read of that data.

[-pcs-size <integer>] - PCS Size

Controls the size of the cache emulated by external-cache PCS. Valid values for this option are integers between 16 and 16383. This option is only used when PCS is enabled. The default value for this option is chosen automatically based on the amount of memory in the controller, and the upper limit is further restricted on controllers with smaller amounts of memory.

[-is-hya-enabled {true|false}] - Is HyA Caching Enabled?

Specifies whether the external-cache module allows caching of blocks targeted for hybrid aggregates. This option is set to true by default when the external-cache is enabled.

Examples

cluster::> system node external-cache modify -node node1 -is-enabled true

The command enables the external-cache feature on node1 .