What OneFS version?  Is SSD L3 enabled? L3 should be disabled for metadata acceleration to work.  L3 is enabled by default.

                One FS version is 8.0.1.0 ... Post disabling the L3 cache I can still find the "enable global namespace acceleration as grayed out as shown above

Check Storage Pools->SmartPools->Edit/View->Edit->"Enable L3 Cache" is set unchecked.  With this checked, the "Enable global namespace acceleration" gets greyed out. Wait for the L3 cache to get flushed before you can use it for GNA.

In addition to the WebGUI there are some more bits of information

available in the CLI:

sysctl efs.bam.layout.ssd.gna_eligible

-> 0 for nor eligible, 1 for eligible

sysctl efs.bam.layout.ssd.gna_global_ssd_node_pct

-> how many percent of nodes with SSDs are required

for GNA to become eligible

sysctl efs.bam.layout.ssd.global_ssd_node_pct

-> how many percent of nodes with SSDs the cluster (thinks it) has

Similar for SSD capacity:

sysctl efs.bam.layout.ssd.gna_global_ssd_storage_pmil

-> how many PER MILLE of capacity required to be SSD

sysctl efs.bam.layout.ssd.global_ssd_storage_pmil

-> how many PER MILLE of capacity the cluster has as SSD

finally:

sysctl efs.bam.layout.ssd.gna_enabled

-> the flag that you found to be greyed out in the WebGUI

sysctl efs.bam.layout.ssd.gna_active

-> 1 for GNA active

hth

Peter

Thanks...... I understand GNA is used for FileSystem MetaData Read Acceleration which provides better performance when compared to L3 cache.

I would like to know how different is GNA when compared to L3 cache in terms of performance and technical difference?

I have gone through the Isilon guides but none explains the difference between these - GNA & L3 cache.