If you have Performance Advisor (Operations Manager 4.x or OnCommand 5) running in the environment you can create a view to monitor the FlashCache cards’ performance. It’s easier on the eyes and brain than watching CLI based stats in my opinion.

 

Here’s the KB on how to do it: https://kb.netapp.com/support/index?page=content&id=1012673

 

There’s an error in the KB at the following line though:

 

dfm option set perfAdvisorShowDiagCounters=enable

 

should be

 

dfm option set perfAdvisorShowDiagCounters=Yes

 

From: toasters-bounces@teaparty.net [mailto:toasters-bounces@teaparty.net] On Behalf Of Woods, Mark
Sent: Monday, December 12, 2011 5:16 PM
To: Jeff Mohler; Fletcher Cocquyt
Cc: toasters@teaparty.net
Subject: RE: Installing & Testing Flash Cache cards

 

This NetApp technical report has some information that will be helpful, including how to exclude/include data from specific volumes.  There is a link to it on the Flash Cache web page of NetApp.com.

 

Flash Cache and PAM Best Practices Guide

http://media.netapp.com/documents/tr-3832.pdf

 

 

 

From: toasters-bounces@teaparty.net [mailto:toasters-bounces@teaparty.net] On Behalf Of Jeff Mohler
Sent: Monday, December 12, 2011 3:03 PM
To: Fletcher Cocquyt
Cc: toasters@teaparty.net
Subject: Re: Installing & Testing Flash Cache cards

 

1)  Just put it in the preferred slot, according to the NOW site docs for your box.
2)  You can use the priority command to set a volume to keep/reuse/never status in PAM  (very nice)
3)  Cache Age, is next to...useless.  It used to mean something, back in 5.0 and earlier...but you wanna use

On Mon, Dec 12, 2011 at 2:39 PM, Fletcher Cocquyt <fcocquyt@stanford.edu> wrote:

We are taking delivery of a couple flash cache cards (512Gb demo units)  soon.

I plan to install them in our standby 3270 cluster then present several cache enabled volumes for various benchmark us cases (Oracle, VMware, Web etc)

 

 Qs:

1 - how easy/hard is the physical installation? Any gotchas to avoid?

2 - can I enable / disable caching on the volumes to help define the benefit flash cache is providing?

3 - how do I best monitor the flash cache metrics (I use cacti to graph "Cache Age" currently)..so..

Check the wafl:wafl:read_io_* stats.  That will show WHERE requested blocks are being service from:
 
wafl:wafl:read_io_type.cache:95%
wafl:wafl:read_io_type.ext_cache:4%
wafl:wafl:read_io_type.disk:0%

Put that together with PAM stats using the stats command to review the status of the ext_cache_obj counters..and you will learn and see a lot.  :)




 

 

thanks

 

-- 
Fletcher Cocquyt
Principal Engineer
Information Resources and Technology (IRT)
Stanford University School of Medicine
<image001.jpg>

Email: fcocquyt@stanford.edu 
Phone: (650) 724-7485

 

 

 

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