Using the Storage Tier Advisor Tool (STAT) to gauge the effectiveness of Easy Tier

One of the valuable features included in the Storwize V7000 storage system at no extra cost is Easy Tier.  Easy Tier continuously monitors data access patterns and will automatically migrate high activity “hot spots” from Hard Disk Drives to Solid State Drives.  Easy Tier is a key feature for helping customers increase the cost effectiveness of SSD drives.

IBM developed a utility called Storage Tier Advisor Tool or STAT, to interpret historical usage data from DS8K, SVC, and Storwize V7000 systems.  When Easy Tier is enabled on a storage pool, historical data is recorded, regardless of whether SSD disks are present or not.  Simply put, STAT reads the historical data files and outputs information that is helpful in determining if there is value to adding SSD storage to a system.  I thought I would take a moment to document how to setup and use the STAT tool.

The first step is to download and install the STAT tool.  It can be found at the following URL: Edit this URL is no longer valid.  The download can be obtained by searching for Storwize V7000 on the IBM Fix Central website.  (

The next step is to enable Easy Tier monitoring on an existing or new storage pool.  This is done from the CLI with command:

IBM_2076:ISV7K7:admin>svctask chmdiskgrp -easytier on “storagepoolname”

 Easy Tier will capture historical performance data over a 24 hour period.  The output file can then be downloaded from the support section of the V7000 as shown below.

Once the output file is downloaded and placed in the STAT directory (Program Files\IBM\STAT), the STAT utility can be ran to generate the reports.

The STAT tool will generate a couple of html pages within the STAT\Data_Files\ directory (System Summary and heat_distribute) which can be used to determine the affect of adding SSD drives to a storage pool.  As you can see from my text example, 12% of the data was determined to be hot, and by migrating that data to SSD storage I would realize a 60-80% performance improvement.

System Summary

Heat Distribution

In case you are curious this storage pool is housing VMware View linked clone disks.  The virtual desktops have been running a simulated office worker workload.

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IBM Flex System Manager Comparison video

In my last post  I provided a short introduction and overview for the new IBM Flex System V7000 Storage Node.  I did not go into great detail about the IBM Flex or PureFlex platforms as there is much more useful information (than I could provide) available already.

I did want to share this video though as it provides a good overview of the Flex System Manager interface, and how it compares to a competitive offering.  If you look closely, and go back and watch any of the Flex launch videos, you can see how the interface has already been updated.

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Introducing the IBM Flex System V7000 Storage Node

Those who follow the IBM announcements may find this old news, but this morning one of the many IBM announcements was the new IBM Flex System V7000 Storage Node.  You read all about the product here.

Along with the IBM Storwize V3700 which we also announced within the last two weeks, it has been a busy quarter for those of us who work primarily with (what I unofficially call) “SAN Volume Controller and the Storwize Disk Family”.

The IBM Flex System V7000 Storage Node adds further integration to the Flex/PureFlex offerings by bringing the V7000 storage controllers into the Flex chassis.  The Flex System V7000 Storage Node will come with version 6.4 of the SVC/Storwize disk family software.  All features and functions available in Storwize V7000 are also available in the Flex System V7000 Storage Node.  In my opinion the major difference right now comes in the way of further integration of connectivity.   Here is a snippet from the announcement which describes this:

Host connectivity: Host connectivity to compute nodes is provided through optional Flex System V7000 control enclosure network cards that connect to the Flex System Enterprise Chassis midplane and its switch modules. Available options are:

  • 10Gb Converged Network Adapter (CNA) 2 Port Daughter Card for FCoE and iSCSI fabric connections
  • 8Gb Fibre Channel (FC) 4 Port Daughter Card for Fibre Channel fabric connections.

Both cards must be installed in pairs (one card per node canister) and the following configurations are supported:

  • Two or four 10Gb CNA cards
  • Two 8Gb FC cards
  • Two 10Gb CNA cards and two 8Gb FC cards

This is really cool because the IBM Flex System V7000 Storage Node connects directly to the Flex System Chassis midplane and the switches which are installed…no cabling necessary.

Look out on other IBMer blogs today for more information about this announcement.


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New SVC/V7000 + VMware Best Practices White Paper Available

I was going through the list of the IBM ISV storage published documents and realized I had not shared this one out on the blog.

VMware vSphere best practices for IBM SAN Volume Controller and the IBM Storwize disk family

Please feel free to leave any feedback about this paper.  There are most likely many topics which are not touched on in this document but the goal was to transfer a presentation which I have presented on the same topic into white paper format.  I expect as gaps are identified and requested, the paper will undergo additions and updates.

If you are interested in other ISV solutions the IBM ISV Storage Solutions Library is a good link to check out.  This site allows you to browse by ISV partner, then storage system.  It is the most comprehensive location to identify IBM storage solution white papers.

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How do you estimate capacity savings with the Real-time Compression Feature?

IBM provides a tool called Comprestimator, which is a command-line utility which can be ran on a variety of hosts and is used to get an estimate of the expected compression rate for block storage devices.

The utility works on the following host types:

  • Red Hat Enterprise Linux Version 5 (64-bit)
  • ESXi 4.0, 5.0
  • AIX V6.1, V7.1
  • HP-UX 11i v3
  • Windows 2003 Server, Windows 2008 Server (32-bit and 64-bit)

More information on the tool and the download location is available at the following URL:

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Stretched IBM SAN Volume Controller certified as a vSphere Metro Storage Cluster solution

This week IBM has completed the VMware vSphere Metro Storage Cluster certification for IBM SAN Volume Controller.  IBM SVC has rich history of being deployed across data centers.  It has been a topic which I’ve talked about on numerous occasions.

This post discusses how SVC can provide a two site vMSC HA/Mobility solution along with replication to a third site with SRM DR failover.

This post is part 1, of a 3 part series where I explain in-depth the SVC solution.

VMware introduced a new HCL category starting with vSphere 5.0 called vSphere Metro Storage Cluster.  It provides official support for storage solutions which qualify and meet the certification.

This is the link to the VMware HCL SVC entry, within it vMSC is now listed.

Along with the HCL entry is a new VMware KB which provides some more details.

Feel free to comment with any questions!


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New Real-time Compression white paper available

I just wanted to share out a quick link to a newly published white paper.

The topic of this paper is IBM SAN Volume Controller & Storwize V7000 Real-time Compression feature with VMware vSphere workloads.

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