Administrator Guide

Solution Verify that all hardware iSCSI initiator WWNs configured on your ESXi hosts are

unique across all ESXi nodes in your Fluid Cache Cluster.

Cluster or Application Has Performance Issues

Possible Cause One or more cache devices are uninstalled, have failed, or do not have the correct

firmware or drivers.

Solution Use Enterprise Manager to check the functionality of the cache devices.

Possible Cause The Compellent storage array is overloaded.

Solution In Enterprise Manager, check the storage latencies and throughput on the cached

volumes. Add more capacity to the Compellent array if necessary.

Possible Cause The application is not making use of the cache.

Solution Make sure the application has an I/O profile that can leverage Fluid Cache, which

accelerates reads, writes, and read-after writes. If the application does, check the

running cache mode for that volume in Enterprise Manager. If necessary, change

cache modes by deleting the volume mapping and creating a new one with a

different cache mode. See Mapping Volumes.

Possible Cause The active data set greatly exceeds the size of the cache pool.

Solution Add more cache devices to increase the size of the cache pool.

Possible Cause Network traffic from outside Fluid Cache is interfering with performance.

Solution The cache network switch is not configured correctly. Configure the ports on the

switch used by Fluid Cache so that they are used solely by Fluid Cache.

Possible Cause The cache network switch is not configured correctly.

Solution Make sure that the switch has the following settings:

• The ports are in Layer 2 mode.

• The ports are in an untagged state.

• The switch firmware is up to date.

• Multicast is enabled.

• Verify that flow control is enabled and DCB is disabled. For Dell Networking

switches, see Configuring the Cache Network Switch. For all other switches,

consult the manufacturer’s documentation.

NOTE: Enabling flow control is a requirement for Fluid Cache.

• For blade enclosure, disable FlexAddress.

You can check network functionality by checking rx_over_errors using the

ethtool -S <interface> command.

Possible Cause Fluid Cache is running on an evaluation license (typically 90 days) and that time

period has been exceeded. You can still access data on cached volumes, but

performance is degraded because the Fluid Cache cluster has been placed in

maintenance mode and caching is no longer active.