EMC VNXe Performance PowerShell Module

vnxePoSH

I thought I would revisit the VNXe performance analysis topic. In 2012 I published some posts around performance analysis of an EMC VNXe storage array. This information applies only to the 1st generation VNXe arrays not to the newer 2nd generation arrays.

In my previous articles I posted a PowerShell module to use to access the VNXe performance database. Since that time I fixed a bug around rollover of timestamps and made a couple other small improvements. The module has also now been published to GitHub.

Here is some background and you can see my previous posts for additional information.

http://muegge.com/blog/emc-vnxe-performance-analysis-with-powershell/

http://muegge.com/blog/emc-vnxe-performance-analysis-with-powershell-part-ii/

The VNXe collects performance statistics in a sqlite database, which can be accessed via scp on the array controllers. It is also available via the diagnostic data package, which can be retried via the system menu in Unisphere. There are a few database file which hold different pieces of performance data about the array. The MTSVNXePerformance PowerShell module provides cmdlets to query the database files and retrieve additional performance information over what is provided in the Unisphere GUI.

I will show some examples of using the module to get performance information. The first one is a simple table with pool capacity information.

The first step is to load the modules, set file path variables, and the sqlite location. This also uses a module to provide charting from the .Net MSChart controls.

The next step is to get some data from the VNXe sqlite tables.

This give us the information we need about pools. So now we can look at rollup Information by using a command like so.

Next we will look at IOPS from the dart summary data. Data is stored in different tables based on type of information and time period. As data is collected it I summarized and moved to historical tables storing longer time periods at less data resolution. Here we are going to get dart store stats which gives us all IO information for each of the data movers

This produces the following charts using the MSChart .Net charting controls.

 

The module can be used to produce complete VNXe performance reports like the one below.

The script that produces the report above is included in the examples folder in the GitHub project.
 

I recieved a fair amount of interest on the first posts around this topic. I hope this update and refresher is still useful to some folks.

Regards,

Dave

EMC VNXe Performance Analysis with PowerShell Part II

I appreciate the positive feedback I have received from the VNXePerformance module so far. I thought I would add to it and provide a script to generate a basic report. The script can be downloaded here.

The script will produce an HTML report and associated graphics with the following information.

  • Capacity Information system and pools(Total and Allocated)
    • Maximum, Minimum, Average, Median
    • Historical graphs for system and each pool
  • Bandwidth usage per protocol
    • Maximum, Minimum, Average, Median
    • Historical graphs
  • IOPS usage per protocol
    • Maximum, Minimum, Average, Median
    • Historical graphs

Here is a sample

The previous post used PowerGadgets for the charting functionality. This tool is not free and it is also not yet supported with PowerShell 3.0. To correct this issue I provided a function in this reporting script which uses the charting functionality in the .Net 4.0 framework. While this fixes the two issues mentioned it does require more work to use, but it will work well for our purposes here. This script uses the VNXePerformance.ps1 module from my previous post and a few new functions to produce an html report and associated graphic files. A command line example to run the script is shown below.

The script uses data provided by the VNXePerformance module and the functions in the script to format and write the report data. Here is a brief description of the functions used.

Out-DataTable – this function is used to convert the PSObject data provided as output from the module functions to the system.data.datatable type. This is required for databinding to produce charts.

Out-LineChart – This function provides chart generating functionality to produce a line chart based on provided datatable and generate a .png graphic file.

Get-SeriesRollup – This function creates summary data (maximum, minimum, average, median) for series data.

The following functions create HTML report output

  • ConvertTo-SeriesRollupHTML
  • Write-ChartHTML
  • Write-BlankHTMLTable
  • Write-HeaderHTMLTable

The first part of the script defines parameters, loads charting assembly, contains the functions declarations and module import.

The next portion of the sets the location of the SQLite database and begins the HTML report string.

The next portion of the script completes the report by using the VNXePerformance module to retrieve object data then output HTML using the script functions.

The final portion of the script closes out the html file and writes it to disk.

This should provide a good starting point to use for reporting. It has much room for improvement. Everyone please comment with information discovered about the SQLite data and information added to the report.

Start-VNXeHTMLPerformanceReport.zip
Regards,

Dave

EMC VNXe Performance Analysis with PowerShell

Hello again, It has been a long time, but the day job takes precedence. Recently, I have been working on a little pet project I thought I would share. The EMC VNXe is a great entry level storage array which has been popular with SMB and remote office branch office deployments in the enterprise. I was recently asked to look at performance on one of these arrays. While investigating this request I discovered the VNXe has reduced functionality around monitoring compared to big brother, VNX. Performance information is collected differently and the VNXe does not currently have the ability to utilize Unisphere Analyzer.

While searching on the web I found the following article http://henriwithani.wordpress.com/2011/12/01/hidden-vnxe-performance-statistics/ . Henri shows where to find additional performance statistics on the VNXe. He also shows how to export the data to CSV for reporting. The VNXe performance data is stored in a public domain C library based SQL database called SQLite. While investigating the use of the SQLite database and tools I discovered there is an ADO.Net provider assembly available for SQLite. Since I am somewhat partial to PowerShell and any .NET object is accessable from PowerShell. I thought I would take a shot at building a PowerShell Module for looking at VNXe performance data.

Here is what I came up with, the VNXePerformance.psm1 PowerShell module. The module currently consists of 21 CmdLets. One CmdLet is to set the location of the SQLite database tables and the remaining 20 are to return data stored in those tables. The CmdLets currently work with the following three SQLite tables:
  • capacity.db
  • stats_basic_summary.db
  • stats_basic_default.db

These three tables appear to hold most of the interesting information so I concentrated on them first. The primary purpose of the module is to query the database and return PowerShell objects from the data. A secondary purpose of the module is to add calculated properties to some of those returned objects. The calculated properties currently implemented provide bytes per second for each of the three IP storage protocols supported NFS, CIFS, and iSCSI and also read and write IO’s per second. This was the first info I needed and was pretty simple to figure out. I plan to add additional calculated fields in the future as I learn more about the data.

Using the module

Install the SQLite ADO.Net Provider Assembly

The VNXePerformance module requires the SQLite ADO.Net Provider to be installed, which can be downloaded from the following page http://system.data.sqlite.org/index.html/doc/trunk/www/downloads.wiki
I recommend using the setup package for the framework and OS version you are using.

The next step is to download the module, unzip it to the modules folder. The proper modules folder can be identified with the $env:PSModulePath variable.

Download the module VnxePerformance.zip

Unzip the module to the PowerShell modules folder, open PowerShell and verify module is available. The VNXePerformance module should be listed when executing the get-module -ListAvailable command, if installed in the proper location.

Then set the following line to the location of the System.Data.SQLite.dll and save changes as necessary. The location defined in the module is the default installation path for the assembly if installed with the prepackaged installation.

We are now ready to use the module so open a PowerShell prompt and import the module.

We can now use the get-command cmdlet to see the new functionality provided by our module.

We can also use the get-help CmdLet to find out the functionality provided by each function. A particulary helpful piece of info in the function help is the example field list and data.

Now we can set the location to our downloaded SQLite database. Please see the following post http://henriwithani.wordpress.com/2011/12/01/hidden-vnxe-performance-statistics/ to learn how to retrieve these files. The command is as follows.

Now we can use the other functions to retrieve data. The following example will give use the last record for the System_Totals table in the capacity.db database.

This also enables some powerful one line commands such as the following which uses a charting tool called PowerGadgets to produce a historical chart that shows total space and allocated space for the system. PowerGadgets is a pay tool which I use, but there are other free ways to do charting such as the MSChart controls included in the .Net framework.

SystemSpace

The following one line command is executed on one of the calculated properties to return basic stats on LUNDiskReadsPerSec

After combining some of these techniques and creating a script. The following simple report was produced for a VNXe system in a lab. The system is only configured for iSCSI and has a single performance pool. The report shows statistics and graphs on Capacity, iSCSI bandwitdh, Disk IO, and Cache.

SystemSpace
PoolSpace
DartBandwidth
FlareIOA
FlareIOB
CReadA
CReadB

The report above shows us some good basic information about this array. The information about other protocols has been omitted as it did not apply to this system. This system has a very consistent and repetitive workload which is primarily read. The read IOPS of approximately 8000 is seems high for this system, but this is also due to the fact that a large portion of these reads are being served from cache. We see a Read Hit Cache ratio of around 60 which shows the majority of reads are being served from cache which would allow for high IO performance. This system is in a lab and has some VM’s running on it so I assume there is a simulator or something of that sort providing the uniform load.

I hope someone finds this useful and if so please provide feedback on potential improvements. I will try to make periodic updates to the module and also post additional examples here. The next topic will be more on the scripting to utilize the module and produce reports.

I would like to end by saying EMC does not provide any documentation on the SQLite database that I could find. So please use the information and provided code with caution and without warranty of any kind. If anyone from EMC reads this and is willing to provide me with documentation on the SQLite database, particularly the field value definitions/explanations, it would be greatly appreciated.

Regards,

Dave