Administrator Guide

Managing a Fluid Cache Cluster
Environment
Configuring Fluid Cache Volumes
A Fluid Cache volume extends a normal Storage Center volume to be contained across the cache devices in a
Fluid Cache cluster as well as permanently stored in the Storage Center volume.
Limitations for Fluid Cache Volumes
There are a number of considerations before utilizing a volume in a Fluid Cache cluster:
• Fluid Cache volumes cannot be expanded
• Fluid Cache volume Read and Write Cache options are not available
• Fluid Cache volumes cannot be the source or destination of Live Volumes
• Fluid Cache volumes cannot be the destination of a replication
• Fluid Cache volumes cannot be part of a synchronous replication or simulation
Mapping Volumes in Fluid Cache
In Enterprise Manager, volume mappings created for a server in a Fluid Cache cluster behave similar to any
other volume mappings. Volumes can be mapped either to an individual server, or to a server cluster (a
“subcluster”) within the Fluid Cache cluster.
NOTE: If you have a shared data application, such as a clustered file system or clustered application, map
volumes to a subcluster.
NOTE: Any applications that were using a volume before it was cached must be modified to use the new
cached volume. When a cached volume is mapped to one or more servers, Fluid Cache creates its own
Linux device file, /dev/fldcX. (The first device mapped is /dev/fldc0, the second is /dev/fldc1,
and so on.) Any application that uses the cached volume must be configured to use the new Fluid Cache
device rather than the /dev/sdX or /dev/mpathX device. If the cached volume is shared by multiple
servers, the
/dev/fldcX device is available on each server.
Mapping Volume to Servers
Before mapping a volume to a server node, create a Fluid Cache cluster (see Creating a Fluid Cache Cluster).
To map a volume to a server:
1 In the Storage view, expand Storage Centers if necessary, and then select the Storage Center that
contains the appropriate volume.
2 In the Storage tab, expand Volumes if necessary, and then locate the volume you want to map.
Fluid Cache for SAN Cluster Creation and Management Operations 25