Administrator Guide

● Data reduction does not support base clone and cloned volumes.
Table 17. Data Reduction Enhancements in FluidFS v6.0 or later
FluidFS v6.0 or later FluidFS v5.0 or earlier
Data reduction is enabled on a per-NAS-cluster basis. Data reduction is enabled on a per-NAS-volume basis.
Data reduction supports deduplication of files that are created
or reside on different domains.
Data reduction is applied per NAS controller, that is, the
same chunks of data that are owned by the different NAS
controllers are not considered duplicates.
The distributed dictionary service detects when it reaches
almost full capacity and doubles in size (depending on
available system storage).
The dictionary size is static and limits the amount of unique
data referenced by the optimization engine.
Date Reduction Age-Based Policies and Archive Mode
By default, data reduction is applied only to files that have not been accessed or modified for 30 days to minimize the impact
of data reduction processing on performance. The number of days after which data reduction is applied to files is configurable
using Storage Manager.
The default number of days is set to 30. When using FluidFS v5 or earlier, you can change the default to as low as 5 days,
and you can start data reduction processing immediately (archive mode). Starting with FluidFS v6, there is no archive mode
available. You can set the Exclude Files Accessed in the Last and Exclude Files Modified in the Last defaults to 1 day
instead of using archive mode.
For more information about enabling and disabling archive mode, see the Dell FluidFS FS8600 Appliance CLI Reference Guide.
Data Reduction Considerations
Consider the following factors when enabling data reduction:
● Data reduction processing has a 5-20% impact on the performance of read operations on reduced data. It does not have any
impact on write operations or read operations on normal data.
● The new (reduced) data and metadata is written to the highest tier in the respective Storage Profile of the FluidFS LUNs.
Standard data progression process is then applied.
● Increased internal traffic during data reduction processing.
● Data is rehydrated for antivirus scanning.
● Data is rehydrated before being replicated to a target NAS volume. If replication is already configured, the data being
reduced was already replicated
● You cannot enable data reduction on a clone NAS volume.
● Data reduction stops automatically when a NAS volume has less than 5 GB of unused space. Therefore, a NAS volume resize
can inadvertently stop data reduction.
Configuring Data Reduction
Data reduction must be enabled at the system level and configured on a per NAS volume basis.
Enable or Disable Data Reduction on the FluidFS Cluster
Data reduction must be enabled at the system level before it will run on NAS volumes on which data reduction is enabled. To
minimize the impact of data reduction processing on system performance, schedule data reduction to run during off-peak times.
Steps
1. In the Storage view, select a FluidFS cluster.
2. Click the File System tab.
3. In the File System view, NAS Pool Advanced Status area, click Edit Data Reduction Settings.
The Edit Data Reduction Settings dialog box opens.
4. Enable or disable data reduction on the FluidFS cluster:
FluidFS Administration
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