Flash Cache Storage Trend Report - Detailed Explaination?

[jeras]

HI!

Is there a document that provides further explanation for the Storage Efficiency Reports that are available from My AutoSupport?  I'm trying to interpret what is being conveyed by these report (specifically the Flash Cache report).

Thanks!

Ken

[andris]

The "about" link takes you (eventually) to this page. It has short explanations for the reports.

https://communities.netapp.com/community/products_and_solutions/efficient_it/my_autosupport_and_autosupport/blog/2011/08/20/my-autosupport-launches-st...

Do you have specific questions that we might be able to address?

[jeras]

I'm specifically looking at the Flash Cache report for my customer's systems.  The short description for this report indicates that this report:

• Flash Cache % calculates Flash Cache enabled capacity as a percentage of the total drive capacity of the system(s)

I'm not quite grasping the value or goal of this report .  When Flash Cache is enabled, the cache is enabled for the entire system. This means that if Flash Cache is enabled, the values shown in this report for Flash Cache enabled capacity will always be 100% since I can only enable all or nothing and I'm just going to see total capacity represented on the other part of the chart.  This chart is not showing me my % cache hit or the number of disk reads saved which is more reflective of the efficiency of Flash Cache for the system. 

[andris]

The Flash Cache report is, as stated, simply reporting enabled capacity. It is not (currently) showing operational efficiency of the Flash Cache component.

This report is not really useful when run against a system. It's more interesting when looking at your entire NetApp infrastructure across a site or company.

Here's an example of the report from a company with a large storage footprint of NetApp systems.

[jeras]

That makes more sense.  Thanks!  That is the type of details that should be added to the explanation for the reports.  Also, perhaps there might be a way to suppress that report from being available in the drop down list when you are looking at an individual system?